Updated: 2025-12-28 03:18:51.03626
Description:
Some mod_proxy configurations on Apache HTTP Server versions 2.4.0 through 2.4.55 allow a HTTP Request Smuggling attack. Configurations are affected when mod_proxy is enabled along with some form of RewriteRule or ProxyPassMatch in which a non-specific pattern matches some portion of the user-supplied request-target (URL) data and is then re-inserted into the proxied request-target using variable substitution. For example, something like: RewriteEngine on RewriteRule "^/here/(.*)" "http://example.com:8080/elsewhere?$1"; [P] ProxyPassReverse /here/ http://example.com:8080/ Request splitting/smuggling could result in bypass of access controls in the proxy server, proxying unintended URLs to existing origin servers, and cache poisoning. Users are recommended to update to at least version 2.4.56 of Apache HTTP Server.
| Links | NIST | CIRCL | RHEL | Ubuntu |
| Severity | Score | |
|---|---|---|
| CVSS Version 2.x | 0.0 | |
| CVSS Version 3.x | CRITICAL | 9.8 |
| OS name | Project name | Version | Score | Severity | Status | Errata | Last updated | Statement |
|---|---|---|---|---|---|---|---|---|
| AlmaLinux 9.2 ESU | httpd | 2.4.53 | 9.8 | CRITICAL | Already Fixed | 2023-11-08 08:35:56 | Will not fix: low score | |
| CentOS 7 ELS | httpd | 2.4.6 | 9.8 | CRITICAL | Already Fixed | 2023-09-19 09:30:21 | Will not fix: low score | |
| CentOS 8.4 ELS | httpd | 2.4.37 | 9.8 | CRITICAL | Released | CLSA-2023:1679000716 | 2023-03-16 21:02:31 | Will not fix: low score |
| CentOS 8.5 ELS | httpd | 2.4.37 | 9.8 | CRITICAL | Released | CLSA-2023:1679000442 | 2023-03-16 17:03:53 | Will not fix: low score |
| Oracle Linux 7 ELS | httpd | 2.4.6 | 9.8 | CRITICAL | In Testing | 2026-01-13 20:38:34 | ||
| Ubuntu 16.04 ELS | apache2 | 2.4.18 | 9.8 | CRITICAL | Released | CLSA-2023:1679943745 | 2023-03-27 17:04:22 | Will not fix: low score |
| Ubuntu 18.04 ELS | apache2 | 2.4.29 | 9.8 | CRITICAL | Already Fixed | 2023-04-28 08:47:46 | Will not fix: low score |