dbcve.org
FedoraOperating system · Fedoraproject

CVE-2022-39957

HIGH · 7.5 CVSS v3.1 Published 2022-09-20
Fix available
A fix is available. Upgrade to 3.2.2 / 3.3.3 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click Patch available

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis

A detailed technical summary for this CVE is being prepared.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
FedoraOperating system
Affected:= 35= 36= 37
Debian LinuxOperating system
Affected:= 10.0
Owasp Modsecurity Core Rule SetApplication
Affected:>= 3.0.0, < 3.2.2>= 3.3.0, < 3.3.3

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 3.2.2 / 3.3.3 or later
Fixed in 3.2.23.3.3
Vendor patch coreruleset.org →
Recommended fix High confidence

OWASP ModSecurity CRS 3.2.2 or 3.3.3 (depending on which branch you are on)

  1. Identify current OWASP ModSecurity Core Rule Set version installed
  2. Download CRS version 3.2.2 (if on 3.0.x, 3.1.x, or 3.2.x branch) or version 3.3.3 (if on 3.3.x branch) from the official OWASP ModSecurity CRS repository
  3. Backup existing CRS configuration files (crs-setup.conf and rules/*.conf)
  4. Replace old CRS rule files with the new version files
  5. Verify crs-setup.conf and custom rule configurations are compatible with the new version
  6. Restart or reload ModSecurity / mod_security to apply the new ruleset
  7. Verify that the bypass vulnerability is remediated by testing with an Accept header containing charset parameter
Caveat Review CRS changelog for rule modifications that may affect existing custom rules or false positive handling; test in staging before production deployment

Generated from the published advisory — verify against the referenced sources before acting.

We can perform the upgrade in your staging environment and verify nothing breaks — typical engagement from $1,950. Get the upgrade done

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2022-39957 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2022-39957 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data