An issue was discovered in Squid 3.x and 4.x through 4.8. It allows attackers to smuggle HTTP requests through frontend software to a Squid instance that splits the HTTP Request pipeline differently. The resulting Response messages corrupt caches (between a client and Squid) with attacker-controlled content at arbitrary URLs. Effects are isolated to software between the attacker client and Squid. There are no effects on Squid itself, nor on any upstream servers. The issue is related to a request header containing whitespace between a header name and a colon.

The remote Redhat Enterprise Linux 7 host has one or more packages installed that are affected by multiple vulnerabilities that have been acknowledged by the vendor but will not be patched.

  - squid: Heap overflow issue in URN processing (CVE-2019-12526)

  - Off-by-one error in the snmpHandleUdp function in snmp_core.cc in Squid 2.x and 3.x, when an SNMP port is     configured, allows remote attackers to cause a denial of service (crash) or possibly execute arbitrary     code via a crafted UDP SNMP request, which triggers a heap-based buffer overflow. (CVE-2014-6270)

  - Squid 3.4.4 through 3.4.11 and 3.5.0.1 through 3.5.1, when Digest authentication is used, allow remote     authenticated users to retain access by leveraging a stale nonce, aka Nonce replay vulnerability.
    (CVE-2014-9749)

Note that Nessus has not tested for these issues but has instead relied on the package manager's report that the package is installed.

The remote Rocky Linux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the RLSA-2020:4743 advisory.

  - An issue was discovered in Squid through 4.7 and 5. When receiving a request, Squid checks its cache to     see if it can serve up a response. It does this by making a MD5 hash of the absolute URL of the request.
    If found, it servers the request. The absolute URL can include the decoded UserInfo (username and     password) for certain protocols. This decoded info is prepended to the domain. This allows an attacker to     provide a username that has special characters to delimit the domain, and treat the rest of the URL as a     path or query string. An attacker could first make a request to their domain using an encoded username,     then when a request for the target domain comes in that decodes to the exact URL, it will serve the     attacker's HTML instead of the real HTML. On Squid servers that also act as reverse proxies, this allows     an attacker to gain access to features that only reverse proxies can use, such as ESI. (CVE-2019-12520)

  - An issue was discovered in Squid through 4.7. When Squid is parsing ESI, it keeps the ESI elements in     ESIContext. ESIContext contains a buffer for holding a stack of ESIElements. When a new ESIElement is     parsed, it is added via addStackElement. addStackElement has a check for the number of elements in this     buffer, but it's off by 1, leading to a Heap Overflow of 1 element. The overflow is within the same     structure so it can't affect adjacent memory blocks, and thus just leads to a crash while processing.
    (CVE-2019-12521)

  - An issue was discovered in Squid before 4.9. When handling a URN request, a corresponding HTTP request is     made. This HTTP request doesn't go through the access checks that incoming HTTP requests go through. This     causes all access checks to be bypassed and allows access to restricted HTTP servers, e.g., an attacker     can connect to HTTP servers that only listen on localhost. (CVE-2019-12523)

  - An issue was discovered in Squid through 4.7. When handling requests from users, Squid checks its rules to     see if the request should be denied. Squid by default comes with rules to block access to the Cache     Manager, which serves detailed server information meant for the maintainer. This rule is implemented via     url_regex. The handler for url_regex rules URL decodes an incoming request. This allows an attacker to     encode their URL to bypass the url_regex check, and gain access to the blocked resource. (CVE-2019-12524)

  - An issue was discovered in Squid before 4.9. URN response handling in Squid suffers from a heap-based     buffer overflow. When receiving data from a remote server in response to an URN request, Squid fails to     ensure that the response can fit within the buffer. This leads to attacker controlled data overflowing in     the heap. (CVE-2019-12526)

  - An issue was discovered in Squid before 4.10. It allows a crafted FTP server to trigger disclosure of     sensitive information from heap memory, such as information associated with other users' sessions or non-     Squid processes. (CVE-2019-12528)

  - An issue was discovered in Squid 2.x through 2.7.STABLE9, 3.x through 3.5.28, and 4.x through 4.7. When     Squid is configured to use Basic Authentication, the Proxy-Authorization header is parsed via uudecode.
    uudecode determines how many bytes will be decoded by iterating over the input and checking its table. The     length is then used to start decoding the string. There are no checks to ensure that the length it     calculates isn't greater than the input buffer. This leads to adjacent memory being decoded as well. An     attacker would not be able to retrieve the decoded data unless the Squid maintainer had configured the     display of usernames on error pages. (CVE-2019-12529)

  - Due to incorrect string termination, Squid cachemgr.cgi 4.0 through 4.7 may access unallocated memory. On     systems with memory access protections, this can cause the CGI process to terminate unexpectedly,     resulting in a denial of service for all clients using it. (CVE-2019-12854)

  - An issue was discovered in Squid 3.x and 4.x through 4.8. Due to incorrect input validation, there is a     heap-based buffer overflow that can result in Denial of Service to all clients using the proxy. Severity     is high due to this vulnerability occurring before normal security checks; any remote client that can     reach the proxy port can trivially perform the attack via a crafted URI scheme. (CVE-2019-18676)

  - An issue was discovered in Squid 3.x and 4.x through 4.8 when the append_domain setting is used (because     the appended characters do not properly interact with hostname length restrictions). Due to incorrect     message processing, it can inappropriately redirect traffic to origins it should not be delivered to.
    (CVE-2019-18677)

  - An issue was discovered in Squid 3.x and 4.x through 4.8. It allows attackers to smuggle HTTP requests     through frontend software to a Squid instance that splits the HTTP Request pipeline differently. The     resulting Response messages corrupt caches (between a client and Squid) with attacker-controlled content     at arbitrary URLs. Effects are isolated to software between the attacker client and Squid. There are no     effects on Squid itself, nor on any upstream servers. The issue is related to a request header containing     whitespace between a header name and a colon. (CVE-2019-18678)

  - An issue was discovered in Squid 2.x, 3.x, and 4.x through 4.8. Due to incorrect data management, it is     vulnerable to information disclosure when processing HTTP Digest Authentication. Nonce tokens contain the     raw byte value of a pointer that sits within heap memory allocation. This information reduces ASLR     protections and may aid attackers isolating memory areas to target for remote code execution attacks.
    (CVE-2019-18679)

  - Squid before 4.9, when certain web browsers are used, mishandles HTML in the host (aka hostname) parameter     to cachemgr.cgi. (CVE-2019-18860)

  - An issue was discovered in Squid before 4.12 and 5.x before 5.0.3. Due to use of a potentially dangerous     function, Squid and the default certificate validation helper are vulnerable to a Denial of Service when     opening a TLS connection to an attacker-controlled server for HTTPS. This occurs because unrecognized     error values are mapped to NULL, but later code expects that each error value is mapped to a valid error     string. (CVE-2020-14058)

  - An issue was discovered in http/ContentLengthInterpreter.cc in Squid before 4.12 and 5.x before 5.0.3. A     Request Smuggling and Poisoning attack can succeed against the HTTP cache. The client sends an HTTP     request with a Content-Length header containing +\ - or an uncommon shell whitespace character prefix     to the length field-value. (CVE-2020-15049)

  - Squid before 4.13 and 5.x before 5.0.4 allows a trusted peer to perform Denial of Service by consuming all     available CPU cycles during handling of a crafted Cache Digest response message. This only occurs when     cache_peer is used with the cache digests feature. The problem exists because peerDigestHandleReply()     livelocking in peer_digest.cc mishandles EOF. (CVE-2020-24606)

  - An issue was discovered in Squid before 4.10. Due to incorrect input validation, it can interpret crafted     HTTP requests in unexpected ways to access server resources prohibited by earlier security filters.
    (CVE-2020-8449)

  - An issue was discovered in Squid before 4.10. Due to incorrect buffer management, a remote client can     cause a buffer overflow in a Squid instance acting as a reverse proxy. (CVE-2020-8450)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The version of squid installed on the remote host is prior to 3.5.20-17. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2-2023-2318 advisory.

  - An issue was discovered in Squid through 4.7. When handling requests from users, Squid checks its rules to     see if the request should be denied. Squid by default comes with rules to block access to the Cache     Manager, which serves detailed server information meant for the maintainer. This rule is implemented via     url_regex. The handler for url_regex rules URL decodes an incoming request. This allows an attacker to     encode their URL to bypass the url_regex check, and gain access to the blocked resource. (CVE-2019-12524)

  - An issue was discovered in Squid 2.x through 2.7.STABLE9, 3.x through 3.5.28, and 4.x through 4.7. When     Squid is configured to use Basic Authentication, the Proxy-Authorization header is parsed via uudecode.
    uudecode determines how many bytes will be decoded by iterating over the input and checking its table. The     length is then used to start decoding the string. There are no checks to ensure that the length it     calculates isn't greater than the input buffer. This leads to adjacent memory being decoded as well. An     attacker would not be able to retrieve the decoded data unless the Squid maintainer had configured the     display of usernames on error pages. (CVE-2019-12529)

  - An issue was discovered in Squid 3.x and 4.x through 4.8 when the append_domain setting is used (because     the appended characters do not properly interact with hostname length restrictions). Due to incorrect     message processing, it can inappropriately redirect traffic to origins it should not be delivered to.
    (CVE-2019-18677)

  - An issue was discovered in Squid 3.x and 4.x through 4.8. It allows attackers to smuggle HTTP requests     through frontend software to a Squid instance that splits the HTTP Request pipeline differently. The     resulting Response messages corrupt caches (between a client and Squid) with attacker-controlled content     at arbitrary URLs. Effects are isolated to software between the attacker client and Squid. There are no     effects on Squid itself, nor on any upstream servers. The issue is related to a request header containing     whitespace between a header name and a colon. (CVE-2019-18678)

  - Squid before 4.9, when certain web browsers are used, mishandles HTML in the host (aka hostname) parameter     to cachemgr.cgi. (CVE-2019-18860)

  - Squid through 4.14 and 5.x through 5.0.5, in some configurations, allows information disclosure because of     an out-of-bounds read in WCCP protocol data. This can be leveraged as part of a chain for remote code     execution as nobody. (CVE-2021-28116)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The version of squid installed on the remote host is prior to 4.10-3. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2SQUID4-2023-007 advisory.

  - An issue was discovered in Squid before 4.9. When handling a URN request, a corresponding HTTP request is     made. This HTTP request doesn't go through the access checks that incoming HTTP requests go through. This     causes all access checks to be bypassed and allows access to restricted HTTP servers, e.g., an attacker     can connect to HTTP servers that only listen on localhost. (CVE-2019-12523)

  - An issue was discovered in Squid 3.3.9 through 3.5.28 and 4.x through 4.7. When Squid is configured to use     Digest authentication, it parses the header Proxy-Authorization. It searches for certain tokens such as     domain, uri, and qop. Squid checks if this token's value starts with a quote and ends with one. If so, it     performs a memcpy of its length minus 2. Squid never checks whether the value is just a single quote     (which would satisfy its requirements), leading to a memcpy of its length minus 1. (CVE-2019-12525)

  - An issue was discovered in Squid before 4.9. URN response handling in Squid suffers from a heap-based     buffer overflow. When receiving data from a remote server in response to an URN request, Squid fails to     ensure that the response can fit within the buffer. This leads to attacker controlled data overflowing in     the heap. (CVE-2019-12526)

  - An issue was discovered in Squid 3.x and 4.x through 4.8. Due to incorrect input validation, there is a     heap-based buffer overflow that can result in Denial of Service to all clients using the proxy. Severity     is high due to this vulnerability occurring before normal security checks; any remote client that can     reach the proxy port can trivially perform the attack via a crafted URI scheme. (CVE-2019-18676)

  - An issue was discovered in Squid 3.x and 4.x through 4.8. It allows attackers to smuggle HTTP requests     through frontend software to a Squid instance that splits the HTTP Request pipeline differently. The     resulting Response messages corrupt caches (between a client and Squid) with attacker-controlled content     at arbitrary URLs. Effects are isolated to software between the attacker client and Squid. There are no     effects on Squid itself, nor on any upstream servers. The issue is related to a request header containing     whitespace between a header name and a colon. (CVE-2019-18678)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Oracle Linux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the ELSA-2020-4743 advisory.

  - An issue was discovered in Squid before 4.10. It allows a crafted FTP server to trigger disclosure of     sensitive information from heap memory, such as information associated with other users' sessions or non-     Squid processes. (CVE-2019-12528)

  - An issue was discovered in Squid before 4.10. Due to incorrect buffer management, a remote client can     cause a buffer overflow in a Squid instance acting as a reverse proxy. (CVE-2020-8450)

  - An issue was discovered in http/ContentLengthInterpreter.cc in Squid before 4.12 and 5.x before 5.0.3. A     Request Smuggling and Poisoning attack can succeed against the HTTP cache. The client sends an HTTP     request with a Content-Length header containing +\ - or an uncommon shell whitespace character prefix     to the length field-value. (CVE-2020-15049)

  - Squid before 4.13 and 5.x before 5.0.4 allows a trusted peer to perform Denial of Service by consuming all     available CPU cycles during handling of a crafted Cache Digest response message. This only occurs when     cache_peer is used with the cache digests feature. The problem exists because peerDigestHandleReply()     livelocking in peer_digest.cc mishandles EOF. (CVE-2020-24606)

  - An issue was discovered in Squid before 4.10. Due to incorrect input validation, it can interpret crafted     HTTP requests in unexpected ways to access server resources prohibited by earlier security filters.
    (CVE-2020-8449)

  - An issue was discovered in Squid through 4.7. When Squid is parsing ESI, it keeps the ESI elements in     ESIContext. ESIContext contains a buffer for holding a stack of ESIElements. When a new ESIElement is     parsed, it is added via addStackElement. addStackElement has a check for the number of elements in this     buffer, but it's off by 1, leading to a Heap Overflow of 1 element. The overflow is within the same     structure so it can't affect adjacent memory blocks, and thus just leads to a crash while processing.
    (CVE-2019-12521)

  - An issue was discovered in Squid before 4.9. When handling a URN request, a corresponding HTTP request is     made. This HTTP request doesn't go through the access checks that incoming HTTP requests go through. This     causes all access checks to be bypassed and allows access to restricted HTTP servers, e.g., an attacker     can connect to HTTP servers that only listen on localhost. (CVE-2019-12523)

  - An issue was discovered in Squid through 4.7. When handling requests from users, Squid checks its rules to     see if the request should be denied. Squid by default comes with rules to block access to the Cache     Manager, which serves detailed server information meant for the maintainer. This rule is implemented via     url_regex. The handler for url_regex rules URL decodes an incoming request. This allows an attacker to     encode their URL to bypass the url_regex check, and gain access to the blocked resource. (CVE-2019-12524)

  - An issue was discovered in Squid before 4.9. URN response handling in Squid suffers from a heap-based     buffer overflow. When receiving data from a remote server in response to an URN request, Squid fails to     ensure that the response can fit within the buffer. This leads to attacker controlled data overflowing in     the heap. (CVE-2019-12526)

  - An issue was discovered in Squid 2.x through 2.7.STABLE9, 3.x through 3.5.28, and 4.x through 4.7. When     Squid is configured to use Basic Authentication, the Proxy-Authorization header is parsed via uudecode.
    uudecode determines how many bytes will be decoded by iterating over the input and checking its table. The     length is then used to start decoding the string. There are no checks to ensure that the length it     calculates isn't greater than the input buffer. This leads to adjacent memory being decoded as well. An     attacker would not be able to retrieve the decoded data unless the Squid maintainer had configured the     display of usernames on error pages. (CVE-2019-12529)

  - Squid before 4.9, when certain web browsers are used, mishandles HTML in the host (aka hostname) parameter     to cachemgr.cgi. (CVE-2019-18860)

  - An issue was discovered in Squid before 4.12 and 5.x before 5.0.3. Due to use of a potentially dangerous     function, Squid and the default certificate validation helper are vulnerable to a Denial of Service when     opening a TLS connection to an attacker-controlled server for HTTPS. This occurs because unrecognized     error values are mapped to NULL, but later code expects that each error value is mapped to a valid error     string. (CVE-2020-14058)

  - An issue was discovered in Squid through 4.7 and 5. When receiving a request, Squid checks its cache to     see if it can serve up a response. It does this by making a MD5 hash of the absolute URL of the request.
    If found, it servers the request. The absolute URL can include the decoded UserInfo (username and     password) for certain protocols. This decoded info is prepended to the domain. This allows an attacker to     provide a username that has special characters to delimit the domain, and treat the rest of the URL as a     path or query string. An attacker could first make a request to their domain using an encoded username,     then when a request for the target domain comes in that decodes to the exact URL, it will serve the     attacker's HTML instead of the real HTML. On Squid servers that also act as reverse proxies, this allows     an attacker to gain access to features that only reverse proxies can use, such as ESI. (CVE-2019-12520)

  - Due to incorrect string termination, Squid cachemgr.cgi 4.0 through 4.7 may access unallocated memory. On     systems with memory access protections, this can cause the CGI process to terminate unexpectedly,     resulting in a denial of service for all clients using it. (CVE-2019-12854)

  - An issue was discovered in Squid 3.x and 4.x through 4.8. Due to incorrect input validation, there is a     heap-based buffer overflow that can result in Denial of Service to all clients using the proxy. Severity     is high due to this vulnerability occurring before normal security checks; any remote client that can     reach the proxy port can trivially perform the attack via a crafted URI scheme. (CVE-2019-18676)

  - An issue was discovered in Squid 3.x and 4.x through 4.8 when the append_domain setting is used (because     the appended characters do not properly interact with hostname length restrictions). Due to incorrect     message processing, it can inappropriately redirect traffic to origins it should not be delivered to.
    (CVE-2019-18677)

  - An issue was discovered in Squid 3.x and 4.x through 4.8. It allows attackers to smuggle HTTP requests     through frontend software to a Squid instance that splits the HTTP Request pipeline differently. The     resulting Response messages corrupt caches (between a client and Squid) with attacker-controlled content     at arbitrary URLs. Effects are isolated to software between the attacker client and Squid. There are no     effects on Squid itself, nor on any upstream servers. The issue is related to a request header containing     whitespace between a header name and a colon. (CVE-2019-18678)

  - An issue was discovered in Squid 2.x, 3.x, and 4.x through 4.8. Due to incorrect data management, it is     vulnerable to information disclosure when processing HTTP Digest Authentication. Nonce tokens contain the     raw byte value of a pointer that sits within heap memory allocation. This information reduces ASLR     protections and may aid attackers isolating memory areas to target for remote code execution attacks.
    (CVE-2019-18679)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote SUSE Linux SLES11 host has a package installed that is affected by multiple vulnerabilities as referenced in the SUSE-SU-2020:14460-1 advisory.

  - An issue was discovered in Squid through 4.7. When handling the tag esi:when when ESI is enabled, Squid     calls ESIExpression::Evaluate. This function uses a fixed stack buffer to hold the expression while it's     being evaluated. When processing the expression, it could either evaluate the top of the stack, or add a     new member to the stack. When adding a new member, there is no check to ensure that the stack won't     overflow. (CVE-2019-12519)

  - An issue was discovered in Squid through 4.7 and 5. When receiving a request, Squid checks its cache to     see if it can serve up a response. It does this by making a MD5 hash of the absolute URL of the request.
    If found, it servers the request. The absolute URL can include the decoded UserInfo (username and     password) for certain protocols. This decoded info is prepended to the domain. This allows an attacker to     provide a username that has special characters to delimit the domain, and treat the rest of the URL as a     path or query string. An attacker could first make a request to their domain using an encoded username,     then when a request for the target domain comes in that decodes to the exact URL, it will serve the     attacker's HTML instead of the real HTML. On Squid servers that also act as reverse proxies, this allows     an attacker to gain access to features that only reverse proxies can use, such as ESI. (CVE-2019-12520)

  - An issue was discovered in Squid through 4.7. When Squid is parsing ESI, it keeps the ESI elements in     ESIContext. ESIContext contains a buffer for holding a stack of ESIElements. When a new ESIElement is     parsed, it is added via addStackElement. addStackElement has a check for the number of elements in this     buffer, but it's off by 1, leading to a Heap Overflow of 1 element. The overflow is within the same     structure so it can't affect adjacent memory blocks, and thus just leads to a crash while processing.
    (CVE-2019-12521)

  - An issue was discovered in Squid before 4.9. When handling a URN request, a corresponding HTTP request is     made. This HTTP request doesn't go through the access checks that incoming HTTP requests go through. This     causes all access checks to be bypassed and allows access to restricted HTTP servers, e.g., an attacker     can connect to HTTP servers that only listen on localhost. (CVE-2019-12523)

  - An issue was discovered in Squid through 4.7. When handling requests from users, Squid checks its rules to     see if the request should be denied. Squid by default comes with rules to block access to the Cache     Manager, which serves detailed server information meant for the maintainer. This rule is implemented via     url_regex. The handler for url_regex rules URL decodes an incoming request. This allows an attacker to     encode their URL to bypass the url_regex check, and gain access to the blocked resource. (CVE-2019-12524)

  - An issue was discovered in Squid 3.3.9 through 3.5.28 and 4.x through 4.7. When Squid is configured to use     Digest authentication, it parses the header Proxy-Authorization. It searches for certain tokens such as     domain, uri, and qop. Squid checks if this token's value starts with a quote and ends with one. If so, it     performs a memcpy of its length minus 2. Squid never checks whether the value is just a single quote     (which would satisfy its requirements), leading to a memcpy of its length minus 1. (CVE-2019-12525)

  - An issue was discovered in Squid before 4.9. URN response handling in Squid suffers from a heap-based     buffer overflow. When receiving data from a remote server in response to an URN request, Squid fails to     ensure that the response can fit within the buffer. This leads to attacker controlled data overflowing in     the heap. (CVE-2019-12526)

  - An issue was discovered in Squid before 4.10. It allows a crafted FTP server to trigger disclosure of     sensitive information from heap memory, such as information associated with other users' sessions or non-     Squid processes. (CVE-2019-12528)

  - An issue was discovered in Squid 2.x through 2.7.STABLE9, 3.x through 3.5.28, and 4.x through 4.7. When     Squid is configured to use Basic Authentication, the Proxy-Authorization header is parsed via uudecode.
    uudecode determines how many bytes will be decoded by iterating over the input and checking its table. The     length is then used to start decoding the string. There are no checks to ensure that the length it     calculates isn't greater than the input buffer. This leads to adjacent memory being decoded as well. An     attacker would not be able to retrieve the decoded data unless the Squid maintainer had configured the     display of usernames on error pages. (CVE-2019-12529)

  - The cachemgr.cgi web module of Squid through 4.7 has XSS via the user_name or auth parameter.
    (CVE-2019-13345)

  - An issue was discovered in Squid 3.x and 4.x through 4.8. Due to incorrect input validation, there is a     heap-based buffer overflow that can result in Denial of Service to all clients using the proxy. Severity     is high due to this vulnerability occurring before normal security checks; any remote client that can     reach the proxy port can trivially perform the attack via a crafted URI scheme. (CVE-2019-18676)

  - An issue was discovered in Squid 3.x and 4.x through 4.8 when the append_domain setting is used (because     the appended characters do not properly interact with hostname length restrictions). Due to incorrect     message processing, it can inappropriately redirect traffic to origins it should not be delivered to.
    (CVE-2019-18677)

  - An issue was discovered in Squid 3.x and 4.x through 4.8. It allows attackers to smuggle HTTP requests     through frontend software to a Squid instance that splits the HTTP Request pipeline differently. The     resulting Response messages corrupt caches (between a client and Squid) with attacker-controlled content     at arbitrary URLs. Effects are isolated to software between the attacker client and Squid. There are no     effects on Squid itself, nor on any upstream servers. The issue is related to a request header containing     whitespace between a header name and a colon. (CVE-2019-18678)

  - An issue was discovered in Squid 2.x, 3.x, and 4.x through 4.8. Due to incorrect data management, it is     vulnerable to information disclosure when processing HTTP Digest Authentication. Nonce tokens contain the     raw byte value of a pointer that sits within heap memory allocation. This information reduces ASLR     protections and may aid attackers isolating memory areas to target for remote code execution attacks.
    (CVE-2019-18679)

  - Squid before 4.9, when certain web browsers are used, mishandles HTML in the host (aka hostname) parameter     to cachemgr.cgi. (CVE-2019-18860)

  - An issue was discovered in Squid before 5.0.2. A remote attacker can replay a sniffed Digest     Authentication nonce to gain access to resources that are otherwise forbidden. This occurs because the     attacker can overflow the nonce reference counter (a short integer). Remote code execution may occur if     the pooled token credentials are freed (instead of replayed as valid credentials). (CVE-2020-11945)

  - An issue was discovered in Squid 5.x before 5.0.3. Due to an Incorrect Synchronization, a Denial of     Service can occur when processing objects in an SMP cache because of an Ipc::Mem::PageStack::pop ABA     problem during access to the memory page/slot management list. (CVE-2020-14059)

  - An issue was discovered in http/ContentLengthInterpreter.cc in Squid before 4.12 and 5.x before 5.0.3. A     Request Smuggling and Poisoning attack can succeed against the HTTP cache. The client sends an HTTP     request with a Content-Length header containing +\ - or an uncommon shell whitespace character prefix     to the length field-value. (CVE-2020-15049)

  - An issue was discovered in Squid before 4.10. Due to incorrect input validation, it can interpret crafted     HTTP requests in unexpected ways to access server resources prohibited by earlier security filters.
    (CVE-2020-8449)

  - An issue was discovered in Squid before 4.10. Due to incorrect buffer management, a remote client can     cause a buffer overflow in a Squid instance acting as a reverse proxy. (CVE-2020-8450)

  - An issue was discovered in Squid before 4.10. Due to incorrect input validation, the NTLM authentication     credentials parser in ext_lm_group_acl may write to memory outside the credentials buffer. On systems with     memory access protections, this can result in the helper process being terminated unexpectedly. This leads     to the Squid process also terminating and a denial of service for all clients using the proxy.
    (CVE-2020-8517)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

According to its self-reported version number, the version of Squid installed on the remote host is prior to 4.9. It is, therefore, affected by multiple vulnerabilities:

 - A heap overflow and possible a remote code execution exist due to incorrect buffer management when processing URN. (CVE-2019-12526)

 - A security bypass exists due to improper input validation. An attacker can gain access to restricted HTTP servers. (CVE-2019-12523)

 - A buffer overflow exists due to incorrect input validation which can result in denial of service to all clients using the proxy. (CVE-2019-18676)

 - A traffic redirect exists due to incorrect message processing with append_domain settings. (CVE-2019-18677)

 - A HTTP request splitting exists due to incorrect message parsing. (CVE-2019-18678)

 - An information disclosure exists due to incorrect data management when processing HTTP Digest Authentication. (CVE-2019-18679) Note that the scanner has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote CentOS Linux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the CESA-2020:4743 advisory.

  - squid: Improper input validation in request allows for proxy manipulation (CVE-2019-12520)

  - squid: Off-by-one error in addStackElement allows for heap buffer overflow and crash (CVE-2019-12521)

  - squid: Improper input validation in URI processor (CVE-2019-12523)

  - squid: Improper access restriction in url_regex may lead to security bypass (CVE-2019-12524)

  - squid: Heap overflow issue in URN processing (CVE-2019-12526)

  - squid: Information Disclosure issue in FTP Gateway (CVE-2019-12528)

  - squid: Out of bounds read in Proxy-Authorization header causes DoS (CVE-2019-12529)

  - squid: Denial of service in cachemgr.cgi (CVE-2019-12854)

  - squid: Buffer overflow in URI processor (CVE-2019-18676)

  - squid: Cross-Site Request Forgery issue in HTTP Request processing (CVE-2019-18677)

  - squid: HTTP Request Splitting issue in HTTP message processing (CVE-2019-18678)

  - squid: Information Disclosure issue in HTTP Digest Authentication (CVE-2019-18679)

  - squid: Mishandled HTML in the host parameter to cachemgr.cgi results in insecure behaviour     (CVE-2019-18860)

  - squid: DoS in TLS handshake (CVE-2020-14058)

  - squid: Request smuggling and poisoning attack against the HTTP cache (CVE-2020-15049)

  - squid: Improper input validation could result in a DoS (CVE-2020-24606)

  - squid: Improper input validation issues in HTTP Request processing (CVE-2020-8449)

  - squid: Buffer overflow in reverse-proxy configurations (CVE-2020-8450)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Redhat Enterprise Linux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2020:4743 advisory.

    Squid is a high-performance proxy caching server for web clients, supporting FTP, Gopher, and HTTP data     objects.

    The following packages have been upgraded to a later upstream version: squid (4.11). (BZ#1829467)

    Security Fix(es):

    * squid: Improper input validation in request allows for proxy manipulation (CVE-2019-12520)

    * squid: Off-by-one error in addStackElement allows for heap buffer overflow and crash (CVE-2019-12521)

    * squid: Improper input validation in URI processor (CVE-2019-12523)

    * squid: Improper access restriction in url_regex may lead to security bypass (CVE-2019-12524)

    * squid: Heap overflow issue in URN processing (CVE-2019-12526)

    * squid: Information Disclosure issue in FTP Gateway (CVE-2019-12528)

    * squid: Out of bounds read in Proxy-Authorization header causes DoS (CVE-2019-12529)

    * squid: Denial of service in cachemgr.cgi (CVE-2019-12854)

    * squid: Buffer overflow in URI processor (CVE-2019-18676)

    * squid: Cross-Site Request Forgery issue in HTTP Request processing (CVE-2019-18677)

    * squid: HTTP Request Splitting issue in HTTP message processing (CVE-2019-18678)

    * squid: Information Disclosure issue in HTTP Digest Authentication (CVE-2019-18679)

    * squid: Mishandled HTML in the host parameter to cachemgr.cgi results in insecure behaviour     (CVE-2019-18860)

    * squid: Improper input validation issues in HTTP Request processing (CVE-2020-8449)

    * squid: Buffer overflow in reverse-proxy configurations (CVE-2020-8450)

    * squid: DoS in TLS handshake (CVE-2020-14058)

    * squid: Request smuggling and poisoning attack against the HTTP cache (CVE-2020-15049)

    * squid: Improper input validation could result in a DoS (CVE-2020-24606)

    For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and     other related information, refer to the CVE page(s) listed in the References section.

    Additional Changes:

    For detailed information on changes in this release, see the Red Hat Enterprise Linux 8.3 Release Notes     linked from the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Multiple security issues were discovered in the Squid proxy caching server, which could result in the bypass of security filters, information disclosure, the execution of arbitrary code or denial of service.

The remote host is affected by the vulnerability described in GLSA-202003-34 (Squid: Multiple vulnerabilities)

    Multiple vulnerabilities have been discovered in Squid. Please review       the CVE identifiers referenced below for details.
  Impact :

    A remote attacker, by sending a specially crafted request, could       possibly execute arbitrary code with the privileges of the process,       obtain sensitive information or cause a Denial of Service condition.
  Workaround :

    There is no known workaround at this time.

This update for squid fixes the following issues :

CVE-2019-12528: Fixed an information disclosure flaw in the FTP gateway (bsc#1162689).

CVE-2019-12526: Fixed potential remote code execution during URN processing (bsc#1156326).

CVE-2019-12523,CVE-2019-18676: Fixed multiple improper validations in URI processing (bsc#1156329).

CVE-2019-18677: Fixed Cross-Site Request Forgery in HTTP Request processing (bsc#1156328).

CVE-2019-18678: Fixed incorrect message parsing which could have led to HTTP request splitting issue (bsc#1156323).

CVE-2019-18679: Fixed information disclosure when processing HTTP Digest Authentication (bsc#1156324).

CVE-2020-8449: Fixed a buffer overflow when squid is acting as reverse-proxy (bsc#1162687).

CVE-2020-8450: Fixed a buffer overflow when squid is acting as reverse-proxy (bsc#1162687).

CVE-2020-8517: Fixed a buffer overflow in ext_lm_group_acl when processing NTLM Authentication credentials (bsc#1162691).

Note that Tenable Network Security has extracted the preceding description block directly from the SUSE security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

According to the versions of the squid package installed, the EulerOS installation on the remote host is affected by the following vulnerabilities :

  - An issue was discovered in Squid 2.x, 3.x, and 4.x     through 4.8. Due to incorrect data management, it is     vulnerable to information disclosure when processing     HTTP Digest Authentication. Nonce tokens contain the     raw byte value of a pointer that sits within heap     memory allocation. This information reduces ASLR     protections and may aid attackers isolating memory     areas to target for remote code execution     attacks.(CVE-2019-18679)

  - An issue was discovered in Squid 3.x and 4.x through     4.8 when the append_domain setting is used (because the     appended characters do not properly interact with     hostname length restrictions). Due to incorrect message     processing, it can inappropriately redirect traffic to     origins it should not be delivered to.(CVE-2019-18677)

  - An issue was discovered in Squid 3.x and 4.x through     4.8. Due to incorrect input validation, there is a     heap-based buffer overflow that can result in Denial of     Service to all clients using the proxy. Severity is     high due to this vulnerability occurring before normal     security checks any remote client that can reach the     proxy port can trivially perform the attack via a     crafted URI scheme.(CVE-2019-18676)

  - An issue was discovered in Squid 3.x and 4.x through     4.8. It allows attackers to smuggle HTTP requests     through frontend software to a Squid instance that     splits the HTTP Request pipeline differently. The     resulting Response messages corrupt caches (between a     client and Squid) with attacker-controlled content at     arbitrary URLs. Effects are isolated to software     between the attacker client and Squid. There are no     effects on Squid itself, nor on any upstream servers.
    The issue is related to a request header containing     whitespace between a header name and a     colon.(CVE-2019-18678)

  - An issue was discovered in Squid before 4.9. URN     response handling in Squid suffers from a heap-based     buffer overflow. When receiving data from a remote     server in response to an URN request, Squid fails to     ensure that the response can fit within the buffer.
    This leads to attacker controlled data overflowing in     the heap.(CVE-2019-12526)

  - An issue was discovered in Squid before 4.9. When     handling a URN request, a corresponding HTTP request is     made. This HTTP request doesn't go through the access     checks that incoming HTTP requests go through. This     causes all access checks to be bypassed and allows     access to restricted HTTP servers, e.g., an attacker     can connect to HTTP servers that only listen on     localhost.(CVE-2019-12523)

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

According to the versions of the squid package installed, the EulerOS installation on the remote host is affected by the following vulnerabilities :

  - An issue was discovered in Squid before 4.9. When     handling a URN request, a corresponding HTTP request is     made. This HTTP request doesn't go through the access     checks that incoming HTTP requests go through. This     causes all access checks to be bypassed and allows     access to restricted HTTP servers, e.g., an attacker     can connect to HTTP servers that only listen on     localhost.(CVE-2019-12523)

  - An issue was discovered in Squid before 4.9. URN     response handling in Squid suffers from a heap-based     buffer overflow. When receiving data from a remote     server in response to an URN request, Squid fails to     ensure that the response can fit within the buffer.
    This leads to attacker controlled data overflowing in     the heap.(CVE-2019-12526)

  - An issue was discovered in Squid 3.x and 4.x through     4.8. Due to incorrect input validation, there is a     heap-based buffer overflow that can result in Denial of     Service to all clients using the proxy. Severity is     high due to this vulnerability occurring before normal     security checks any remote client that can reach the     proxy port can trivially perform the attack via a     crafted URI scheme.(CVE-2019-18676)

  - An issue was discovered in Squid 3.x and 4.x through     4.8 when the append_domain setting is used (because the     appended characters do not properly interact with     hostname length restrictions). Due to incorrect message     processing, it can inappropriately redirect traffic to     origins it should not be delivered to.(CVE-2019-18677)

  - An issue was discovered in Squid 3.x and 4.x through     4.8. It allows attackers to smuggle HTTP requests     through frontend software to a Squid instance that     splits the HTTP Request pipeline differently. The     resulting Response messages corrupt caches (between a     client and Squid) with attacker-controlled content at     arbitrary URLs. Effects are isolated to software     between the attacker client and Squid. There are no     effects on Squid itself, nor on any upstream servers.
    The issue is related to a request header containing     whitespace between a header name and a     colon.(CVE-2019-18678)

  - An issue was discovered in Squid 2.x, 3.x, and 4.x     through 4.8. Due to incorrect data management, it is     vulnerable to information disclosure when processing     HTTP Digest Authentication. Nonce tokens contain the     raw byte value of a pointer that sits within heap     memory allocation. This information reduces ASLR     protections and may aid attackers isolating memory     areas to target for remote code execution     attacks.(CVE-2019-18679)

Note that Tenable Network Security has extracted the preceding description block directly from the EulerOS security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

It was found that Squid, a high-performance proxy caching server for web clients, has been affected by the following security vulnerabilities.

CVE-2019-12526

URN response handling in Squid suffers from a heap-based buffer overflow. When receiving data from a remote server in response to an URN request, Squid fails to ensure that the response can fit within the buffer. This leads to attacker controlled data overflowing in the heap.

CVE-2019-18677

When the append_domain setting is used (because the appended characters do not properly interact with hostname length restrictions), it can inappropriately redirect traffic to origins it should not be delivered to. This happens because of incorrect message processing.

CVE-2019-18678

A programming error allows attackers to smuggle HTTP requests through frontend software to a Squid instance that splits the HTTP Request pipeline differently. The resulting Response messages corrupt caches (between a client and Squid) with attacker-controlled content at arbitrary URLs. Effects are isolated to software between the attacker client and Squid. There are no effects on Squid itself, nor on any upstream servers. The issue is related to a request header containing whitespace between a header name and a colon.

CVE-2019-18679

Due to incorrect data management, Squid is vulnerable to information disclosure when processing HTTP Digest Authentication. Nonce tokens contain the raw byte value of a pointer that sits within heap memory allocation. This information reduces ASLR protections and may aid attackers isolating memory areas to target for remote code execution attacks.

For Debian 8 'Jessie', these problems have been fixed in version 3.4.8-6+deb8u9.

We recommend that you upgrade your squid3 packages.

NOTE: Tenable Network Security has extracted the preceding description block directly from the DLA security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

The remote Ubuntu 16.04 LTS / 18.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-4213-1 advisory.

    Jeriko One and Kristoffer Danielsson discovered that Squid incorrectly handled certain URN requests. A     remote attacker could possibly use this issue to bypass access checks and access restricted servers. This     issue was only addressed in Ubuntu 19.04 and Ubuntu 19.10. (CVE-2019-12523)

    Jeriko One discovered that Squid incorrectly handed URN responses. A remote attacker could use this issue     to cause Squid to crash, resulting in a denial of service, or possibly execute arbitrary code.
    (CVE-2019-12526)

    Alex Rousskov discovered that Squid incorrectly handled certain strings. A remote attacker could possibly     use this issue to cause Squid to crash, resulting in a denial of service. This issue only affected Ubuntu     19.04. (CVE-2019-12854)

    Jeriko One and Kristoffer Danielsson discovered that Squid incorrectly handled certain input. A remote     attacker could use this issue to cause Squid to crash, resulting in a denial of service, or possibly     execute arbitrary code. This issue was only addressed in Ubuntu 19.04 and Ubuntu 19.10. (CVE-2019-18676)

    Kristoffer Danielsson discovered that Squid incorrectly handled certain messages. This issue could result     in traffic being redirected to origins it should not be delivered to. (CVE-2019-18677)

    Rgis Leroy discovered that Squid incorrectly handled certain HTTP request headers. A remote attacker     could use this to smuggle HTTP requests and corrupt caches with arbitrary content. (CVE-2019-18678)

    David Fifield discovered that Squid incorrectly handled HTTP Digest Authentication. A remote attacker     could possibly use this issue to obtain pointer contents and bypass ASLR protections. (CVE-2019-18679)

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

New version update - squid 4.9

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website.
Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

This update for squid to version 4.9 fixes the following issues :

Security issues fixed :

CVE-2019-13345: Fixed multiple cross-site scripting vulnerabilities in cachemgr.cgi (bsc#1140738).

CVE-2019-12526: Fixed potential remote code execution during URN processing (bsc#1156326).

CVE-2019-12523,CVE-2019-18676: Fixed multiple improper validations in URI processing (bsc#1156329).

CVE-2019-18677: Fixed Cross-Site Request Forgery in HTTP Request processing (bsc#1156328).

CVE-2019-18678: Fixed incorrect message parsing which could have led to HTTP request splitting issue (bsc#1156323).

CVE-2019-18679: Fixed information disclosure when processing HTTP Digest Authentication (bsc#1156324).

Other issues addressesd :

  - Fixed DNS failures when peer name was configured with     any upper case characters

  - Fixed several rock cache_dir corruption issues

Note that Tenable Network Security has extracted the preceding description block directly from the SUSE security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

This update for squid to version 4.9 fixes the following issues :

Security issues fixed :

  - CVE-2019-13345: Fixed multiple cross-site scripting     vulnerabilities in cachemgr.cgi (bsc#1140738).

  - CVE-2019-12526: Fixed potential remote code execution     during URN processing (bsc#1156326).

  - CVE-2019-12523,CVE-2019-18676: Fixed multiple improper     validations in URI processing (bsc#1156329).

  - CVE-2019-18677: Fixed Cross-Site Request Forgery in HTTP     Request processing (bsc#1156328).

  - CVE-2019-18678: Fixed incorrect message parsing which     could have led to HTTP request splitting issue     (bsc#1156323).

  - CVE-2019-18679: Fixed information disclosure when     processing HTTP Digest Authentication (bsc#1156324).

Other issues addressed :

  - Fixed DNS failures when peer name was configured with     any upper case characters

  - Fixed several rock cache_dir corruption issues

This update was imported from the SUSE:SLE-15:Update update project.

This update for squid to version 4.9 fixes the following issues :

Security issues fixed :

CVE-2019-13345: Fixed multiple cross-site scripting vulnerabilities in cachemgr.cgi (bsc#1140738).

CVE-2019-12526: Fixed potential remote code execution during URN processing (bsc#1156326).

CVE-2019-12523,CVE-2019-18676: Fixed multiple improper validations in URI processing (bsc#1156329).

CVE-2019-18677: Fixed Cross-Site Request Forgery in HTTP Request processing (bsc#1156328).

CVE-2019-18678: Fixed incorrect message parsing which could have led to HTTP request splitting issue (bsc#1156323).

CVE-2019-18679: Fixed information disclosure when processing HTTP Digest Authentication (bsc#1156324).

Other issues addressed :

  - Fixed DNS failures when peer name was configured with     any upper case characters

  - Fixed several rock cache_dir corruption issues

Note that Tenable Network Security has extracted the preceding description block directly from the SUSE security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

ID	Name	Product	Family	Severity
198536	RHEL 7 : squid (Unpatched Vulnerability)	Nessus	Red Hat Local Security Checks	critical
184691	Rocky Linux 8 : squid:4 (RLSA-2020:4743)	Nessus	Rocky Linux Local Security Checks	critical
183925	Amazon Linux 2 : squid (ALAS-2023-2318)	Nessus	Amazon Linux Local Security Checks	critical
182047	Amazon Linux 2 : squid (ALASSQUID4-2023-007)	Nessus	Amazon Linux Local Security Checks	critical
180917	Oracle Linux 8 : squid:4 (ELSA-2020-4743)	Nessus	Oracle Linux Local Security Checks	critical
150657	SUSE SLES11 Security Update : squid3 (SUSE-SU-2020:14460-1)	Nessus	SuSE Local Security Checks	critical
112694	Squid < 4.9 Multiple Vulnerabilities	Web App Scanning	Component Vulnerability	critical
145969	CentOS 8 : squid:4 (CESA-2020:4743)	Nessus	CentOS Local Security Checks	critical
142412	RHEL 8 : squid:4 (RHSA-2020:4743)	Nessus	Red Hat Local Security Checks	critical
136430	Debian DSA-4682-1 : squid - security update	Nessus	Debian Local Security Checks	critical
134640	GLSA-202003-34 : Squid: Multiple vulnerabilities	Nessus	Gentoo Local Security Checks	critical
134561	SUSE SLES12 Security Update : squid (SUSE-SU-2020:0661-1)	Nessus	SuSE Local Security Checks	critical
133934	EulerOS 2.0 SP5 : squid (EulerOS-SA-2020-1133)	Nessus	Huawei Local Security Checks	critical
132627	EulerOS 2.0 SP8 : squid (EulerOS-SA-2020-1034)	Nessus	Huawei Local Security Checks	critical
131961	Debian DLA-2028-1 : squid3 security update	Nessus	Debian Local Security Checks	critical
131723	Ubuntu 16.04 LTS / 18.04 LTS : Squid vulnerabilities (USN-4213-1)	Nessus	Ubuntu Local Security Checks	critical
131714	Fedora 31 : 7:squid (2019-9538783033)	Nessus	Fedora Local Security Checks	critical
131707	Fedora 30 : 7:squid (2019-0b16cbdd0e)	Nessus	Fedora Local Security Checks	critical
131386	SUSE SLES12 Security Update : squid (SUSE-SU-2019:3067-1)	Nessus	SuSE Local Security Checks	critical
131220	openSUSE Security Update : squid (openSUSE-2019-2541)	Nessus	SuSE Local Security Checks	critical
131219	openSUSE Security Update : squid (openSUSE-2019-2540)	Nessus	SuSE Local Security Checks	critical
131070	SUSE SLES15 Security Update : squid (SUSE-SU-2019:2975-1)	Nessus	SuSE Local Security Checks	critical

Detections

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CVE-2019-18678

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