CVE-2022-39955: debian debian_linux Incorrect Authorization
Vulnerability summary
CVE-2022-39955 is a critical (CVSS 9.8) Incorrect Authorization vulnerability in debian debian_linux. EPSS estimates a 1.42% chance of exploitation in the next 30 days, higher than 72.4% 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 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.
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 · calculated9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- OSV · DebianEcosystem advisory · calculated9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
1.42%
Chance of exploitation in the next 30 days
Percentile
72%
Versus all other CVEs
30-day change
+0.01 pp
From 1.41% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected 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