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Advisory details: ubuntu_osv / UBUNTU-CVE-2022-39955
Advisory ID ubuntu_osv/UBUNTU-CVE-2022-39955
Aliases CVE-2022-39955
Summary 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.
Status Published
Exploitability 0.5
Weighted Severity 8.8
Risk 4.4
Affected and Fixed Packages Package Details
Introduced and Fixed Package Commit Patches Package Commit Patches Details
Weaknesses (0)
There are no known CWE.
System Score Found at
cvssv3.1 7.3 https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2022/UBUNTU-CVE-2022-39955.json
cvssv3.1 9.8 https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2022/UBUNTU-CVE-2022-39955.json
ubuntu-priority low https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2022/UBUNTU-CVE-2022-39955.json
Reference id Reference type URL
https://ubuntu.com/security/CVE-2022-39955
https://www.cve.org/CVERecord?id=CVE-2022-39955
crs-version-3-3-3-and-3-2-2-covering-several-cves Other https://coreruleset.org/20220919/crs-version-3-3-3-and-3-2-2-covering-several-cves/
No exploits are available.

No EPSS data available for this advisory.

Patch URL
There are no known patches.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L Found at https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2022/UBUNTU-CVE-2022-39955.json
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Found at https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2022/UBUNTU-CVE-2022-39955.json
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none

There are no SSVC decisions available.