CVE-2022-39957: debian debian_linux Protection Mechanism Failure
Vulnerability summary
CVE-2022-39957 is a high (CVSS 7.5) Protection Mechanism Failure vulnerability in debian debian_linux. EPSS estimates a 1.00% chance of exploitation in the next 30 days, higher than 62% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 3Timeline
- 20-09-2022PublishedVulnerability first disclosed.
- 03-11-2025Last modifiedVulnerability information updated.
Description
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.
CVSS metrics
4 scores · 4 sources · 1 version- CVE.orgCNA7.3HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:LDiffers
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS trend
Probability
1.00%
Chance of exploitation in the next 30 days
Percentile
62%
Versus all other CVEs
30-day change
+0.01 pp
From 0.99% on 18-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root cause- CWE-693Protection Mechanism FailureThe product does not use or incorrectly uses a protection mechanism that provides sufficient defense against directed attacks against the product.
- CWE-116Improper Encoding or Escaping of OutputThe product prepares a structured message for communication with another component, but encoding or escaping of the data is either missing or done incorrectly. As a result, the intended structure of the message is not preserved.
Affected systems
Debian2 products
- modsecurity-crs< 3.3.4-1
- debian_linuxEOL10.0
Owasp2 products
- modsecurity core rule set≥ 3.0.0, < 3.1.0 | ≥ 3.1.0, < 3.2.0 | ≥ unspecified, ≤ 3.2.1 | ≥ unspecified, ≤ 3.3.2
- owasp_modsecurity_core_rule_set≥ 3.0.0, < 3.2.2 | ≥ 3.3.0, < 3.3.3
Fedoraproject1 product
- fedoraEOL35 | 36 | 37
Ubuntu1 product
- modsecurity-crsAll versions (No fix recorded)
4 vendors · 6 products
References
10 links- coreruleset.org/20220919/crs-version-3-3-3-and-3-2-2-covering-several-cves/REPORTPatchVendor Advisory
- lists.fedoraproject.org/archives/…Vendor Advisory
- lists.fedoraproject.org/archives/…Vendor Advisory
- lists.fedoraproject.org/archives/…Vendor Advisory
- security.gentoo.org/glsa/202305-25Vendor Advisory