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.

This plugin has been deprecated as it does not adhere to established standards for this style of check.

The remote Rocky Linux 8 host has packages installed that are affected by a vulnerability as referenced in the RLSA-2022:1939 advisory.

  - 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 this issue 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 4.15-1. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2SQUID4-2023-004 advisory.

  - 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)

  - An issue was discovered in Squid before 4.15 and 5.x before 5.0.6. Due to a buffer-management bug, it     allows a denial of service. When resolving a request with the urn: scheme, the parser leaks a small amount     of memory. However, there is an unspecified attack methodology that can easily trigger a large amount of     memory consumption. (CVE-2021-28651)

  - An issue was discovered in Squid before 4.15 and 5.x before 5.0.6. Due to incorrect parser validation, it     allows a Denial of Service attack against the Cache Manager API. This allows a trusted client to trigger     memory leaks that. over time, lead to a Denial of Service via an unspecified short query string. This     attack is limited to clients with Cache Manager API access privilege. (CVE-2021-28652)

  - An issue was discovered in Squid 4.x before 4.15 and 5.x before 5.0.6. If a remote server sends a certain     response header over HTTP or HTTPS, there is a denial of service. This header can plausibly occur in     benign network traffic. (CVE-2021-28662)

  - An issue was discovered in Squid before 4.15 and 5.x before 5.0.6. Due to a memory-management bug, it is     vulnerable to a Denial of Service attack (against all clients using the proxy) via HTTP Range request     processing. (CVE-2021-31806)

  - An issue was discovered in Squid before 4.15 and 5.x before 5.0.6. An integer overflow problem allows a     remote server to achieve Denial of Service when delivering responses to HTTP Range requests. The issue     trigger is a header that can be expected to exist in HTTP traffic without any malicious intent.
    (CVE-2021-31807)

  - An issue was discovered in Squid before 4.15 and 5.x before 5.0.6. Due to an input-validation bug, it is     vulnerable to a Denial of Service attack (against all clients using the proxy). A client sends an HTTP     Range request to trigger this. (CVE-2021-31808)

  - Squid before 4.15 and 5.x before 5.0.6 allows remote servers to cause a denial of service (affecting     availability to all clients) via an HTTP response. The issue trigger is a header that can be expected to     exist in HTTP traffic without any malicious intent by the server. (CVE-2021-33620)

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

The remote Debian 10 / 11 host has packages installed that are affected by multiple vulnerabilities as referenced in the dsa-5171 advisory.

  - 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)

  - In Squid 3.x through 3.5.28, 4.x through 4.17, and 5.x before 5.6, due to improper buffer management, a     Denial of Service can occur when processing long Gopher server responses. (CVE-2021-46784)

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

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

  - 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 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 packages installed, the EulerOS installation on the remote host is affected by the following vulnerabilities :

  - 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)

  - 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 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.

The remote Oracle Linux 8 host has packages installed that are affected by a vulnerability as referenced in the ELSA-2022-1939 advisory.

    - Resolves: #1941506 - CVE-2021-28116 squid:4/squid: out-of-bounds read in WCCP       protocol data may lead to information disclosure

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

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

The remote AlmaLinux 8 host has packages installed that are affected by a vulnerability as referenced in the ALSA-2022:1939 advisory.

  - 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 this issue 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 a vulnerability as referenced in the RHSA-2022:1939 advisory.

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

    Security Fix(es):

    * squid: out-of-bounds read in WCCP protocol data may lead to information disclosure (CVE-2021-28116)

    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 8.6 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 this issue 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 a vulnerability as referenced in the CESA-2022:1939 advisory.

  - squid: out-of-bounds read in WCCP protocol data may lead to information disclosure (CVE-2021-28116)

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

The remote SUSE Linux SUSE15 host has a package installed that is affected by a vulnerability as referenced in the openSUSE-SU-2021:1419-1 advisory.

  - 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 this issue but has instead relied only on the application's self-reported version number.

The remote SUSE Linux SLES15 host has a package installed that is affected by a vulnerability as referenced in the SUSE- SU-2021:3485-1 advisory.

  - 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 this issue but has instead relied only on the application's self-reported version number.

The remote SUSE Linux SUSE15 host has a package installed that is affected by a vulnerability as referenced in the openSUSE-SU-2021:3485-1 advisory.

  - 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 this issue but has instead relied only on the application's self-reported version number.

The remote SUSE Linux SLES12 / SLES_SAP12 host has a package installed that is affected by a vulnerability as referenced in the SUSE-SU-2021:3334-1 advisory.

  - 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 this issue but has instead relied only on the application's self-reported version number.

The remote Ubuntu 18.04 LTS / 20.04 LTS host has packages installed that are affected by a vulnerability as referenced in the USN-5104-1 advisory.

    Lyu discovered that Squid incorrectly handled WCCP protocol data. A remote attacker could use this issue     to cause Squid to crash, resulting in a denial of service, or possibly obtain sensitive information.

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

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

An update of the squid package has been released.

The remote host is affected by the vulnerability described in GLSA-202105-14 (Squid: Multiple vulnerabilities)

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

    A remote attacker could send a specially crafted request, possibly       resulting in a Denial of Service condition or information leak.
  Workaround :

    There is no known workaround at this time.

ID	Name	Product	Family	Severity
195586	RHEL 7 : squid (Unpatched Vulnerability) (deprecated)	Nessus	Red Hat Local Security Checks	high
184552	Rocky Linux 8 : squid:4 (RLSA-2022:1939)	Nessus	Rocky Linux Local Security Checks	medium
183925	Amazon Linux 2 : squid (ALAS-2023-2318)	Nessus	Amazon Linux Local Security Checks	critical
181987	Amazon Linux 2 : squid (ALASSQUID4-2023-004)	Nessus	Amazon Linux Local Security Checks	medium
162562	Debian DSA-5171-1 : squid - security update	Nessus	Debian Local Security Checks	medium
162356	EulerOS 2.0 SP5 : squid (EulerOS-SA-2022-1916)	Nessus	Huawei Local Security Checks	medium
161564	EulerOS 2.0 SP3 : squid (EulerOS-SA-2022-1766)	Nessus	Huawei Local Security Checks	high
161279	Oracle Linux 8 : squid:4 (ELSA-2022-1939)	Nessus	Oracle Linux Local Security Checks	medium
161127	AlmaLinux 8 : squid:4 (ALSA-2022:1939)	Nessus	Alma Linux Local Security Checks	medium
161029	RHEL 8 : squid:4 (RHSA-2022:1939)	Nessus	Red Hat Local Security Checks	medium
160901	CentOS 8 : squid:4 (CESA-2022:1939)	Nessus	CentOS Local Security Checks	medium
156309	EulerOS 2.0 SP8 : squid (EulerOS-SA-2021-2815)	Nessus	Huawei Local Security Checks	medium
154755	openSUSE 15 Security Update : squid (openSUSE-SU-2021:1419-1)	Nessus	SuSE Local Security Checks	medium
154304	SUSE SLES15 Security Update : squid (SUSE-SU-2021:3485-1)	Nessus	SuSE Local Security Checks	medium
154286	openSUSE 15 Security Update : squid (openSUSE-SU-2021:3485-1)	Nessus	SuSE Local Security Checks	medium
153998	SUSE SLES12 Security Update : squid (SUSE-SU-2021:3334-1)	Nessus	SuSE Local Security Checks	medium
153888	Ubuntu 18.04 LTS / 20.04 LTS : Squid vulnerability (USN-5104-1)	Nessus	Ubuntu Local Security Checks	medium
151967	Photon OS 4.0: Squid PHSA-2021-4.0-0063	Nessus	PhotonOS Local Security Checks	medium
151955	Photon OS 3.0: Squid PHSA-2021-3.0-0269	Nessus	PhotonOS Local Security Checks	medium
150021	GLSA-202105-14 : Squid: Multiple vulnerabilities	Nessus	Gentoo Local Security Checks	high

Detections

Analytics

CVE-2021-28116

medium

Tenable Plugins

high

medium

critical

medium

medium

medium

high

medium

medium

medium

medium

medium

medium

medium

medium

medium

medium

medium

medium

high