The OWASP ModSecurity Core Rule Set (CRS) is affected by a partial rule set bypass by submitting a specially crafted HTTP Content-Type header field that indicates multiple character encoding schemes. A vulnerable back-end can potentially be exploited by declaring multiple Content-Type "charset" names and therefore bypassing the configurable CRS Content-Type header "charset" allow list. An encoded payload can bypass CRS detection this way and may then be decoded by the backend. The legacy CRS versions 3.0.x and 3.1.x are affected, as well as the currently supported versions 3.2.1 and 3.3.2. Integrators and users are advised to upgrade to 3.2.2 and 3.3.3 respectively.

The remote Debian 11 host has a package installed that is affected by multiple vulnerabilities as referenced in the dla-4265 advisory.

    - -------------------------------------------------------------------------     Debian LTS Advisory DLA-4265-1                debian-lts@lists.debian.org     https://www.debian.org/lts/security/                          Adrian Bunk     August 08, 2025                               https://wiki.debian.org/LTS
    - -------------------------------------------------------------------------

    Package        : modsecurity-crs     Version        : 3.3.4-1~deb11u1     CVE ID         : CVE-2020-22669 CVE-2022-39955 CVE-2022-39956 CVE-2022-39957                      CVE-2022-39958     Debian Bug     : 1021137

    Multiple issues have been fixed in modsecurity-crs, a set of generic     attack detection rules for use with ModSecurity.

    CVE-2020-22669

        SQL injection bypass

    CVE-2022-39955

        Partial rule set bypass

    CVE-2022-39956

        Partial rule set bypass

    CVE-2022-39957

        Response body bypass

    CVE-2022-39958

        Response body bypass

    For Debian 11 bullseye, these problems have been fixed in version     3.3.4-1~deb11u1.

    We recommend that you upgrade your modsecurity-crs packages.

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

    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 Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - The OWASP ModSecurity Core Rule Set (CRS) is affected by a partial rule set bypass by submitting a     specially crafted HTTP Content-Type header field that indicates multiple character encoding schemes. A     vulnerable back-end can potentially be exploited by declaring multiple Content-Type charset names and     therefore bypassing the configurable CRS Content-Type header charset allow list. An encoded payload can     bypass CRS detection this way and may then be decoded by the backend. The legacy CRS versions 3.0.x and     3.1.x are affected, as well as the currently supported versions 3.2.1 and 3.3.2. Integrators and users are     advised to upgrade to 3.2.2 and 3.3.3 respectively. (CVE-2022-39955)

Note that Nessus relies on the presence of the package as reported by the vendor.

The remote Fedora 37 host has packages installed that are affected by multiple vulnerabilities as referenced in the FEDORA-2022-1fd73a5285 advisory.

    - version update
    - security fixes

Tenable has extracted the preceding description block directly from the Fedora 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 remote host is affected by the vulnerability described in GLSA-202305-25 (OWASP ModSecurity Core Rule Set: Multiple Vulnerabilities)

  - OWASP ModSecurity Core Rule Set 3.1.x before 3.1.2, 3.2.x before 3.2.1, and 3.3.x before 3.3.2 is affected     by a Request Body Bypass via a trailing pathname. (CVE-2021-35368)

  - The OWASP ModSecurity Core Rule Set (CRS) is affected by a partial rule set bypass by submitting a     specially crafted HTTP Content-Type header field that indicates multiple character encoding schemes. A     vulnerable back-end can potentially be exploited by declaring multiple Content-Type charset names and     therefore bypassing the configurable CRS Content-Type header charset allow list. An encoded payload can     bypass CRS detection this way and may then be decoded by the backend. The legacy CRS versions 3.0.x and     3.1.x are affected, as well as the currently supported versions 3.2.1 and 3.3.2. Integrators and users are     advised to upgrade to 3.2.2 and 3.3.3 respectively. (CVE-2022-39955)

  - The OWASP ModSecurity Core Rule Set (CRS) is affected by a partial rule set bypass for HTTP multipart     requests by submitting a payload that uses a character encoding scheme via the Content-Type or the     deprecated Content-Transfer-Encoding multipart MIME header fields that will not be decoded and inspected     by the web application firewall engine and the rule set. The multipart payload will therefore bypass     detection. A vulnerable backend that supports these encoding schemes can potentially be exploited. The     legacy CRS versions 3.0.x and 3.1.x are affected, as well as the currently supported versions 3.2.1 and     3.3.2. Integrators and users are advised upgrade to 3.2.2 and 3.3.3 respectively. The mitigation against     these vulnerabilities depends on the installation of the latest ModSecurity version (v2.9.6 / v3.0.8).
    (CVE-2022-39956)

  - The OWASP ModSecurity Core Rule Set (CRS) is affected by a response body bypass. A client can issue an     HTTP Accept header field containing an optional charset parameter in order to receive the response in an     encoded form. Depending on the charset, this response can not be decoded by the web application     firewall. A restricted resource, access to which would ordinarily be detected, may therefore bypass     detection. The legacy CRS versions 3.0.x and 3.1.x are affected, as well as the currently supported     versions 3.2.1 and 3.3.2. Integrators and users are advised to upgrade to 3.2.2 and 3.3.3 respectively.
    (CVE-2022-39957)

  - The OWASP ModSecurity Core Rule Set (CRS) is affected by a response body bypass to sequentially exfiltrate     small and undetectable sections of data by repeatedly submitting an HTTP Range header field with a small     byte range. A restricted resource, access to which would ordinarily be detected, may be exfiltrated from     the backend, despite being protected by a web application firewall that uses CRS. Short subsections of a     restricted resource may bypass pattern matching techniques and allow undetected access. The legacy CRS     versions 3.0.x and 3.1.x are affected, as well as the currently supported versions 3.2.1 and 3.3.2.
    Integrators and users are advised to upgrade to 3.2.2 and 3.3.3 respectively and to configure a CRS     paranoia level of 3 or higher. (CVE-2022-39958)

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 host has a package installed that is affected by multiple vulnerabilities as referenced in the dla-3293 advisory.

    -------------------------------------------------------------------------     Debian LTS Advisory DLA-3293-1                debian-lts@lists.debian.org     https://www.debian.org/lts/security/                         Tobias Frost     January 30, 2023                              https://wiki.debian.org/LTS
    -------------------------------------------------------------------------

    Package        : modsecurity-crs     Version        : 3.2.3-0+deb10u3     CVE ID         : CVE-2018-16384 CVE-2020-22669 CVE-2021-35368 CVE-2022-39955                      CVE-2022-39956 CVE-2022-39957 CVE-2022-39958     Debian Bug     : 924352 992000 1021137

    Multiple issues were found in modsecurity-crs, a set of generic attack     detection rules for use with ModSecurity or compatible web application     firewalls, which allows remote attackers to bypass the web applications     firewall.

    If you are using modsecurity-crs with apache2 / libapache2-modsecurity, please     make sure to review your modsecurity configuration, usually     /etc/modsecurity/modsecurity.conf, against the updated recommended     configration, available in /etc/modsecurity/modsecurity.conf-recommended:
    Some of the changes to the recommended rules are required to avoid WAF bypasses     in certain circumstances.

    Please note that CVE-2022-39956 requires an updated modsecurity-apache packge,     which has been previously uploaded to buster-security, see Debian LTS Advisory     DLA-3283-1 for details.

    If you are using some other solution in connection with the     modsecurity-ruleset, for example one that it is using libmodsecurity3, your     solution might error out with an error message like Error creating rule:
    Unknown variable: MULTIPART_PART_HEADERS. In this case you can disable the     mitigation for CVE-2022-29956 by removing the rule file     REQUEST-922-MULTIPART-ATTACK.conf.  However, be aware that this will disable     the protection and could allow attackers to bypass your Web Application     Firewall.

    There is no package in Debian which depends on libmodsecurity3, so if you are     only using software which is available from Debian, you are not affected by     this limitation.

    Kudos to @airween for the support and help while perparing the update.

    CVE-2018-16384

        A SQL injection bypass (aka PL1 bypass) exists in OWASP ModSecurity Core Rule         Set (owasp-modsecurity-crs) through v3.1.0-rc3 via {`a`b} where a is a special         function name (such as if) and b is the SQL statement to be executed.

    CVE-2020-22669

        Modsecurity owasp-modsecurity-crs 3.2.0 (Paranoia level at PL1) has a SQL         injection bypass vulnerability. Attackers can use the comment characters and         variable assignments in the SQL syntax to bypass Modsecurity WAF protection and         implement SQL injection attacks on Web applications.

    CVE-2022-39955

        The OWASP ModSecurity Core Rule Set (CRS) is affected by a partial rule set         bypass by submitting a specially crafted HTTP Content-Type header field that         indicates multiple character encoding schemes. A vulnerable back-end can         potentially be exploited by declaring multiple Content-Type charset names and         therefore bypassing the configurable CRS Content-Type header charset allow         list. An encoded payload can bypass CRS detection this way and may then be         decoded by the backend. The legacy CRS versions 3.0.x and 3.1.x are affected,         as well as the currently supported versions 3.2.1 and 3.3.2. Integrators and         users are advised to upgrade to 3.2.2 and 3.3.3 respectively.

    CVE-2022-39956

        The OWASP ModSecurity Core Rule Set (CRS) is affected by a partial rule set         bypass for HTTP multipart requests by submitting a payload that uses a         character encoding scheme via the Content-Type or the deprecated         Content-Transfer-Encoding multipart MIME header fields that will not be decoded         and inspected by the web application firewall engine and the rule set. The         multipart payload will therefore bypass detection. A vulnerable backend that         supports these encoding schemes can potentially be exploited. The legacy CRS         versions 3.0.x and 3.1.x are affected, as well as the currently supported         versions 3.2.1 and 3.3.2. Integrators and users are advised upgrade to 3.2.2         and 3.3.3 respectively. The mitigation against these vulnerabilities depends on         the installation of the latest ModSecurity version (v2.9.6 / v3.0.8).

    CVE-2022-39957

        The OWASP ModSecurity Core Rule Set (CRS) is affected by a response body         bypass. A client can issue an HTTP Accept header field containing an optional         charset parameter in order to receive the response in an encoded form.
        Depending on the charset, this response can not be decoded by the web         application firewall. A restricted resource, access to which would ordinarily         be detected, may therefore bypass detection. The legacy CRS versions 3.0.x and         3.1.x are affected, as well as the currently supported versions 3.2.1 and         3.3.2. Integrators and users are advised to upgrade to 3.2.2 and 3.3.3         respectively.

    CVE-2022-39958

        The OWASP ModSecurity Core Rule Set (CRS) is affected by a response body bypass         to sequentially exfiltrate small and undetectable sections of data by         repeatedly submitting an HTTP Range header field with a small byte range. A         restricted resource, access to which would ordinarily be detected, may be         exfiltrated from the backend, despite being protected by a web application         firewall that uses CRS. Short subsections of a restricted resource may bypass         pattern matching techniques and allow undetected access. The legacy CRS         versions 3.0.x and 3.1.x are affected, as well as the currently supported         versions 3.2.1 and 3.3.2. Integrators and users are advised to upgrade to 3.2.2         and 3.3.3 respectively and to configure a CRS paranoia level of 3 or higher.

    For Debian 10 buster, these problems have been fixed in version     3.2.3-0+deb10u3.

    We recommend that you upgrade your modsecurity-crs packages.

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

    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     Attachment:
    signature.asc     Description: PGP signature

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 remote Fedora 35 host has packages installed that are affected by multiple vulnerabilities as referenced in the FEDORA-2022-85a85c84b3 advisory.

    - version update
    - security update

Tenable has extracted the preceding description block directly from the Fedora 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 remote Fedora 36 host has packages installed that are affected by multiple vulnerabilities as referenced in the FEDORA-2022-90708b46e3 advisory.

    - version update
    - security update

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

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

ID	Name	Product	Family	Type	Severity
246422	Debian dla-4265 : modsecurity-crs - security update	Nessus	Debian Local Security Checks	Local	critical
224964	Linux Distros Unpatched Vulnerability : CVE-2022-39955	Nessus	Misc.	Local	critical
211415	Fedora 37 : mod_security / mod_security_crs (2022-1fd73a5285)	Nessus	Fedora Local Security Checks	Local	critical
176193	GLSA-202305-25 : OWASP ModSecurity Core Rule Set: Multiple Vulnerabilities	Nessus	Gentoo Local Security Checks	Local	critical
170888	Debian dla-3293 : modsecurity-crs - security update	Nessus	Debian Local Security Checks	Local	critical
169232	Fedora 35 : mod_security / mod_security_crs (2022-85a85c84b3)	Nessus	Fedora Local Security Checks	Local	critical
169143	Fedora 36 : mod_security / mod_security_crs (2022-90708b46e3)	Nessus	Fedora Local Security Checks	Local	critical

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