Auth bypass in Owasp Modsecurity Core Rule Set
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.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.012 (69.0th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 69th percentile — 69.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.012 · newest: 0.012 · change: +0.000
Affected products
- Owasp Modsecurity Core Rule Set — versions 3.0.x, 3.1.x, unspecified
- Owasp Modsecurity Core Rule Set
- Debian Linux — versions 10.0
- Fedoraproject Fedora — versions 35, 36, 37
Weakness classification (CWE)
Public proof-of-concept exploits
References
- coreruleset.org/20220919/crs-version-3-3-3-and-3-2-2-covering-several-cves/ (Patch, Vendor Advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- lists.debian.org/debian-lts-announce/2023/01/msg00033.html (mailing-list, Mailing List, Third Party Advisory)
- security.gentoo.org/glsa/202305-25 (vendor-advisory)
- af854a3a-2127-422b-91ae-364da2661108
Frequently asked questions
- What is CVE-2022-39958?
- CVE-2022-39958 is a high-severity vulnerability in Owasp Modsecurity Core Rule Set, classified under Incorrect Authorization. CVSS score: 7.5/10. Published 2022-09-20.
- How severe is CVE-2022-39958?
- High severity. CVSS v3 base score is 7.5 out of 10.
- Is CVE-2022-39958 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.