# CVE-2023-24021: modsecurity-apache: Incorrect handling of '\0' bytes in file uploads in ModSecurity before 2.9.7 may allow for Web Application Firewall b...

CVE-2023-24021 is fixed in 2 products on 1 platform, first by libapache2-mod-security2 2.9.2-1ubuntu0.1~esm1, released January 20, 2023. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2023-24021
- Priority: High
- CVSS: 7.5 (high)
- EPSS: 0.0093
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jan 20, 2023

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | libapache2-mod-security2 Ubuntu 18.04.6 LTS (bionic) | 2.9.2-1ubuntu0.1~esm1 | [libapache2-mod-security2 2.9.2-1ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libapache2-mod-security2-2.9.2-1ubuntu0.1-esm1.md) | Jan 20, 2023 |
| Linux | libapache2-mod-security2 Ubuntu 20.04 LTS (focal) | 2.9.3-1ubuntu0.1 | [libapache2-mod-security2 2.9.3-1ubuntu0.1](https://patchblox.com/security/data/fix/linux/ubuntu-focal-libapache2-mod-security2-2.9.3-1ubuntu0.1.md) | Jan 20, 2023 |
| Linux | libapache2-mod-security2 Ubuntu 22.04.1 LTS (jammy) | 2.9.5-1ubuntu0.1~esm1 | [libapache2-mod-security2 2.9.5-1ubuntu0.1~esm1](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-libapache2-mod-security2-2.9.5-1ubuntu0.1-esm1.md) | Jan 20, 2023 |
| Linux | modsecurity-apache Debian 12.15 (bookworm) | 2.9.7-1 | [DEBIAN-CVE-2023-24021](https://patchblox.com/security/data/fix/linux/debian-cve-2023-24021.md) | Jan 20, 2023 |
| Linux | modsecurity-apache Debian 13.5 (trixie) | 2.9.7-1 | [DEBIAN-CVE-2023-24021](https://patchblox.com/security/data/fix/linux/debian-cve-2023-24021.md) | Jan 20, 2023 |
| Linux | modsecurity-apache Debian 14 | 2.9.7-1 | [DEBIAN-CVE-2023-24021](https://patchblox.com/security/data/fix/linux/debian-cve-2023-24021.md) | Jan 20, 2023 |

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Data as of 2026-11-09T07:25:28Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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