Apache HTTP Server versions 2.4.6 to 2.4.46 mod_proxy_wstunnel configured on an URL that is not necessarily Upgraded by the origin server was tunneling the whole connection regardless, thus allowing for subsequent requests on the same connection to pass through with no HTTP validation, authentication or authorization possibly configured.

The remote Redhat Enterprise Linux 8 host has one or more packages installed that are affected by a vulnerability that has been acknowledged by the vendor but will not be patched.

  - httpd:  mod_proxy_wstunnel tunneling of non Upgraded connection (CVE-2019-17567)

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

The remote Debian 10 host has packages installed that are affected by multiple vulnerabilities as referenced in the dla-3818 advisory.

    - -------------------------------------------------------------------------     Debian LTS Advisory DLA-3818-1                debian-lts@lists.debian.org     https://www.debian.org/lts/security/                   Bastien Roucaris     May 24, 2024                                  https://wiki.debian.org/LTS
    - -------------------------------------------------------------------------

    Package        : apache2     Version        : 2.4.59-1~deb10u1     CVE ID         : CVE-2019-17567 CVE-2023-31122 CVE-2023-38709 CVE-2023-45802                      CVE-2024-24795 CVE-2024-27316     Debian Bug     : 1068412

    Multiple vulnerabilities have been discovered in the Apache HTTP server,     which may result in HTTP response splitting, denial of service, or     authorization bypass.

    CVE-2019-17567

         mod_proxy_wstunnel configured on an URL that is not          necessarily Upgraded by the origin server was tunneling          the whole connection regardless, thus allowing for subsequent requests          on the same connection to pass through with no HTTP validation,          authentication or authorization possibly configured.

    CVE-2023-31122

        An Out-of-bounds Read vulnerability was found in mod_macro.

    CVE-2023-38709

        A faulty input validation was found in the core of Apache         that allows malicious or exploitable backend/content generators         to split HTTP responses.

    CVE-2023-45802

        When an HTTP/2 stream was reset (RST frame) by a client, there was a         time window were the request's memory resources were not reclaimed         immediately. Instead, de-allocation was deferred to connection close.
        A client could send new requests and resets, keeping the connection         busy and open and causing the memory footprint to keep on growing.
        On connection close, all resources were reclaimed, but the process         might run out of memory before that.

    CVE-2024-24795

        HTTP Response splitting in multiple modules in Apache HTTP Server         allows an attacker that can inject malicious response headers into         backend applications to cause an HTTP desynchronization attack.

    CVE-2024-27316

        HTTP/2 incoming headers exceeding the limit are temporarily         buffered in nghttp2 in order to generate an informative HTTP         413 response. If a client does not stop sending headers, this         leads to memory exhaustion.

    For Debian 10 buster, these problems have been fixed in version     2.4.59-1~deb10u1.

    Please note that the fix of CVE-2024-24795, may break unrelated     CGI-BIN scripts. As part of the security fix, the Apache webserver     mod_cgi module has stopped relaying the Content-Length field     of the HTTP reply header from the CGI programs back to the client     in cases where the connection is to be closed and the client     is able to read until end-of-file. You may restore legacy     behavior for trusted scripts by adding the following configuration     environment variable to the     Apache configuration, scoped to the <Directory> entry or     entries in which scripts are being served via CGI,     SetEnv ap_trust_cgilike_cl yes.
    The definitive fix is to read the whole input,     re-allocating the input buffer to fit as more input is received     in CGI-BIN scripts, and and to not trust that     CONTENT_LENGTH variable is always present.

    We recommend that you upgrade your apache2 packages.

    For the detailed security status of apache2 please refer to     its security tracker page at:
    https://security-tracker.debian.org/tracker/apache2

    Further information about Debian LTS security advisories, how to apply     these updates to your system and frequently asked questions can be     found at: https://wiki.debian.org/LTS

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

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 httpd installed on the remote CBL Mariner 2.0 host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the CVE-2019-17567 advisory.

  - Apache HTTP Server versions 2.4.6 to 2.4.46 mod_proxy_wstunnel configured on an URL that is not     necessarily Upgraded by the origin server was tunneling the whole connection regardless, thus allowing for     subsequent requests on the same connection to pass through with no HTTP validation, authentication or     authorization possibly configured. (CVE-2019-17567)

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

The remote host is affected by the vulnerability described in GLSA-202107-38 (Apache: Multiple vulnerabilities)

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

    Please review the referenced CVE identifiers for details.
  Workaround :

    There is no known workaround at this time.

The remote Redhat Enterprise Linux 7 / 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2021:4614 advisory.

    This release adds the new Apache HTTP Server 2.4.37 Service Pack 10 packages that are part of the JBoss     Core Services offering.

    This release serves as a replacement for Red Hat JBoss Core Services Apache HTTP Server 2.4.37 Service     Pack 9 and includes bug fixes and enhancements. Refer to the Release Notes for information on the most     significant bug fixes and enhancements included in this release.

    Security Fix(es):

    * httpd: Single zero byte stack overflow in mod_auth_digest (CVE-2020-35452)
    * httpd: mod_session NULL pointer dereference in parser (CVE-2021-26690)
    * httpd: Heap overflow in mod_session (CVE-2021-26691)
    * httpd: mod_proxy_wstunnel tunneling of non Upgraded connection (CVE-2019-17567)
    * httpd: MergeSlashes regression (CVE-2021-30641)
    * httpd: mod_proxy NULL pointer dereference (CVE-2020-13950)
    * jbcs-httpd24-openssl: openssl: NULL pointer dereference in X509_issuer_and_serial_hash()     (CVE-2021-23841)
    * openssl: Read buffer overruns processing ASN.1 strings (CVE-2021-3712)
    * openssl: integer overflow in CipherUpdate (CVE-2021-23840)
    * pcre: buffer over-read in JIT when UTF is disabled (CVE-2019-20838)
    * pcre: integer overflow in libpcre (CVE-2020-14155)

    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.

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.

An update of the httpd package has been released.

The version of httpd24 installed on the remote host is prior to 2.4.48-1.92. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS-2021-1514 advisory.

  - Apache HTTP Server versions 2.4.6 to 2.4.46 mod_proxy_wstunnel configured on an URL that is not     necessarily Upgraded by the origin server was tunneling the whole connection regardless, thus allowing for     subsequent requests on the same connection to pass through with no HTTP validation, authentication or     authorization possibly configured. (CVE-2019-17567)

  - Apache HTTP Server versions 2.4.0 to 2.4.46 Unprivileged local users can stop httpd on Windows     (CVE-2020-13938)

  - Apache HTTP Server versions 2.4.41 to 2.4.46 mod_proxy_http can be made to crash (NULL pointer     dereference) with specially crafted requests using both Content-Length and Transfer-Encoding headers,     leading to a Denial of Service (CVE-2020-13950)

  - Apache HTTP Server versions 2.4.0 to 2.4.46 A specially crafted Digest nonce can cause a stack overflow in     mod_auth_digest. There is no report of this overflow being exploitable, nor the Apache HTTP Server team     could create one, though some particular compiler and/or compilation option might make it possible, with     limited consequences anyway due to the size (a single byte) and the value (zero byte) of the overflow     (CVE-2020-35452)

  - Apache HTTP Server versions 2.4.0 to 2.4.46 A specially crafted Cookie header handled by mod_session can     cause a NULL pointer dereference and crash, leading to a possible Denial Of Service (CVE-2021-26690)

  - In Apache HTTP Server versions 2.4.0 to 2.4.46 a specially crafted SessionHeader sent by an origin server     could cause a heap overflow (CVE-2021-26691)

  - Apache HTTP Server versions 2.4.39 to 2.4.46 Unexpected matching behavior with 'MergeSlashes OFF'     (CVE-2021-30641)

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 httpd installed on the remote host is prior to 2.4.48-2. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2-2021-1674 advisory.

  - Apache HTTP Server versions 2.4.6 to 2.4.46 mod_proxy_wstunnel configured on an URL that is not     necessarily Upgraded by the origin server was tunneling the whole connection regardless, thus allowing for     subsequent requests on the same connection to pass through with no HTTP validation, authentication or     authorization possibly configured. (CVE-2019-17567)

  - Apache HTTP Server versions 2.4.0 to 2.4.46 Unprivileged local users can stop httpd on Windows     (CVE-2020-13938)

  - Apache HTTP Server versions 2.4.41 to 2.4.46 mod_proxy_http can be made to crash (NULL pointer     dereference) with specially crafted requests using both Content-Length and Transfer-Encoding headers,     leading to a Denial of Service (CVE-2020-13950)

  - Apache HTTP Server versions 2.4.0 to 2.4.46 A specially crafted Digest nonce can cause a stack overflow in     mod_auth_digest. There is no report of this overflow being exploitable, nor the Apache HTTP Server team     could create one, though some particular compiler and/or compilation option might make it possible, with     limited consequences anyway due to the size (a single byte) and the value (zero byte) of the overflow     (CVE-2020-35452)

  - Apache HTTP Server versions 2.4.0 to 2.4.46 A specially crafted Cookie header handled by mod_session can     cause a NULL pointer dereference and crash, leading to a possible Denial Of Service (CVE-2021-26690)

  - In Apache HTTP Server versions 2.4.0 to 2.4.46 a specially crafted SessionHeader sent by an origin server     could cause a heap overflow (CVE-2021-26691)

  - Apache HTTP Server versions 2.4.39 to 2.4.46 Unexpected matching behavior with 'MergeSlashes OFF'     (CVE-2021-30641)

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

The Apache httpd reports :

- moderate: mod_proxy_wstunnel tunneling of non Upgraded connections (CVE-2019-17567)

- moderate: Improper Handling of Insufficient Privileges (CVE-2020-13938)

- low: mod_proxy_http NULL pointer dereference (CVE-2020-13950)

- low: mod_auth_digest possible stack overflow by one nul byte (CVE-2020-35452)

- low: mod_session NULL pointer dereference (CVE-2021-26690)

- low: mod_session response handling heap overflow (CVE-2021-26691)

- moderate: Unexpected URL matching with 'MergeSlashes OFF' (CVE-2021-30641)

- important: NULL pointer dereference on specially crafted HTTP/2 request (CVE-2021-31618)

The version of httpd installed on the remote host is prior to 2.4.48-1. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2-2021-1659 advisory.

  - Apache HTTP Server versions 2.4.6 to 2.4.46 mod_proxy_wstunnel configured on an URL that is not     necessarily Upgraded by the origin server was tunneling the whole connection regardless, thus allowing for     subsequent requests on the same connection to pass through with no HTTP validation, authentication or     authorization possibly configured. (CVE-2019-17567)

  - Apache HTTP Server versions 2.4.0 to 2.4.46 Unprivileged local users can stop httpd on Windows     (CVE-2020-13938)

  - Apache HTTP Server versions 2.4.41 to 2.4.46 mod_proxy_http can be made to crash (NULL pointer     dereference) with specially crafted requests using both Content-Length and Transfer-Encoding headers,     leading to a Denial of Service (CVE-2020-13950)

  - Apache HTTP Server versions 2.4.0 to 2.4.46 A specially crafted Digest nonce can cause a stack overflow in     mod_auth_digest. There is no report of this overflow being exploitable, nor the Apache HTTP Server team     could create one, though some particular compiler and/or compilation option might make it possible, with     limited consequences anyway due to the size (a single byte) and the value (zero byte) of the overflow     (CVE-2020-35452)

  - Apache HTTP Server versions 2.4.0 to 2.4.46 A specially crafted Cookie header handled by mod_session can     cause a NULL pointer dereference and crash, leading to a possible Denial Of Service (CVE-2021-26690)

  - In Apache HTTP Server versions 2.4.0 to 2.4.46 a specially crafted SessionHeader sent by an origin server     could cause a heap overflow (CVE-2021-26691)

  - Apache HTTP Server versions 2.4.39 to 2.4.46 Unexpected matching behavior with 'MergeSlashes OFF'     (CVE-2021-30641)

  - Apache HTTP Server protocol handler for the HTTP/2 protocol checks received request headers against the     size limitations as configured for the server and used for the HTTP/1 protocol as well. On violation of     these restrictions and HTTP response is sent to the client with a status code indicating why the request     was rejected. This rejection response was not fully initialised in the HTTP/2 protocol handler if the     offending header was the very first one received or appeared in a a footer. This led to a NULL pointer     dereference on initialised memory, crashing reliably the child process. Since such a triggering HTTP/2     request is easy to craft and submit, this can be exploited to DoS the server. This issue affected     mod_http2 1.15.17 and Apache HTTP Server version 2.4.47 only. Apache HTTP Server 2.4.47 was never     released. (CVE-2021-31618)

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 banner, the version of Apache running on the remote host is 2.4.x prior to 2.4.48. It is, therefore, affected by multiple vulnerabilities:

 - Unexpected <Location> section matching with 'MergeSlashes OFF'. (CVE-2021-30641)

 - mod_auth_digest: possible stack overflow by one nul byte while validating the Digest nonce. (CVE-2020-35452)

 - mod_session: Fix possible crash due to NULL pointer dereference, which could be used to cause a Denial of Service with a malicious backend server and SessionHeader. (CVE-2021-26691)

 - mod_session: Fix possible crash due to NULL pointer dereference, which could be used to cause a Denial of Service. (CVE-2021-26690)

 - mod_proxy_http: Fix possible crash due to NULL pointer dereference, which could be used to cause a Denial of Service. (CVE-2020-13950)

 - Windows: Prevent local users from stopping the httpd process (CVE-2020-13938)

 - mod_proxy_wstunnel, mod_proxy_http: Handle Upgradable protocols end-to-end negotiation. (CVE-2019-17567)

 - mod_http2: Fix a potential NULL pointer dereference. (CVE-2021-31618)

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

New httpd packages are available for Slackware 14.0, 14.1, 14.2, and
-current to fix security issues.

The version of Apache httpd installed on the remote host is prior to 2.4.47. It is, therefore, affected by multiple vulnerabilities as referenced in the 2.4.47 changelog:

  - Unexpected <Location> section matching with 'MergeSlashes OFF' (CVE-2021-30641)

  - mod_auth_digest: possible stack overflow by one nul byte while validating the Digest nonce. (CVE-2020-35452)

  - mod_session: Fix possible crash due to NULL pointer dereference, which could be used to cause a Denial of Service     with a malicious backend server and SessionHeader. (CVE-2021-26691)

  - mod_session: Fix possible crash due to NULL pointer dereference, which could be used to cause a Denial of Service.
    (CVE-2021-26690)

  - mod_proxy_http: Fix possible crash due to NULL pointer dereference, which could be used to cause a Denial of     Service. (CVE-2020-13950)

  - Windows: Prevent local users from stopping the httpd process (CVE-2020-13938)

  - mod_proxy_wstunnel, mod_proxy_http: Handle Upgradable protocols end-to-end negotiation. (CVE-2019-17567)

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

ID	Name	Product	Family	Severity
198699	RHEL 8 : httpd (Unpatched Vulnerability)	Nessus	Red Hat Local Security Checks	medium
197924	Debian dla-3818 : apache2 - security update	Nessus	Debian Local Security Checks	medium
172823	CBL Mariner 2.0 Security Update: httpd (CVE-2019-17567)	Nessus	MarinerOS Local Security Checks	medium
156972	GLSA-202107-38 : Apache: Multiple vulnerabilities	Nessus	Gentoo Local Security Checks	critical
155223	RHEL 7 / 8 : Red Hat JBoss Core Services Apache HTTP Server 2.4.37 SP10 (RHSA-2021:4614)	Nessus	Red Hat Local Security Checks	critical
153184	Photon OS 3.0: Httpd PHSA-2021-3.0-0257	Nessus	PhotonOS Local Security Checks	high
151522	Amazon Linux AMI : httpd24 (ALAS-2021-1514)	Nessus	Amazon Linux Local Security Checks	critical
151436	Photon OS 1.0: Httpd PHSA-2021-1.0-0409	Nessus	PhotonOS Local Security Checks	critical
151272	Amazon Linux 2 : httpd (ALAS-2021-1674)	Nessus	Amazon Linux Local Security Checks	critical
151196	Photon OS 2.0: Httpd PHSA-2021-2.0-0365	Nessus	PhotonOS Local Security Checks	critical
151010	FreeBSD : Apache httpd -- Multiple vulnerabilities (cce76eca-ca16-11eb-9b84-d4c9ef517024)	Nessus	FreeBSD Local Security Checks	critical
150983	Amazon Linux 2 : httpd (ALAS-2021-1659)	Nessus	Amazon Linux Local Security Checks	critical
112806	Apache 2.4.x < 2.4.48 Multiple Vulnerabilities	Web App Scanning	Component Vulnerability	critical
150334	Slackware 14.0 / 14.1 / 14.2 / current : httpd (SSA:2021-158-01)	Nessus	Slackware Local Security Checks	critical
150280	Apache 2.4.x < 2.4.47 Multiple Vulnerabilities	Nessus	Web Servers	critical

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CVE-2019-17567

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