CVE-2023-24021
Trustwave Modsecurity ≤ 2.9.7
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:NCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2023-24021 is a high-severity Improper Null Termination (CWE-170) vulnerability in Trustwave Modsecurity. Its CVSS base score is 7.5 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Data Obfuscation (T1001); ranked in the top 41% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-28085
Vulnerability Data
Incorrect handling of '\0' bytes in file uploads in ModSecurity before 2.9.7 may allow for Web Application Firewall bypasses and buffer over-reads on the Web Application Firewall when executing rules that read the FILES_TMP_CONTENT collection.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly enforce correct string/array termination via coding standards, reviews, and static analysis.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
A.8.25 mandates secure SDLC practices including secure coding guidelines, developer training, security testing and checkpoints that reach improper null termination as a coding defect, but leaves a bounded remainder (e.g. outsourced development without full assurance, inconsistent application of guidelines across languages or legacy code, and defects that slip past testing per the SA-3 vs CWE-89 precedent).
A.8.26 requires identifying and specifying security requirements (including resilience against SQL injection or buffer overflows) but does not itself implement any mechanism that stops null-termination errors from being introduced or exploited; the weakness can still be present and exploitable.
A.8.27 mandates establishing and applying secure engineering principles (including secure coding, hardening, and design review) but does not itself remove existing instances of null-termination defects already present in code; per the verb definition and anchors, testing finds while only direct code change removes, and this clause reaches neither first-party code defects nor the removal act
Secure coding standards directly require correct null termination of strings and arrays.
Security testing in development can detect missing or incorrect null terminators before release.