CVE-2011-3639: apache http_server Improper Input Validation

Vulnerability summary

CVE-2011-3639 is a medium (CVSS 4.3) Improper Input Validation vulnerability in apache http_server. EPSS estimates a 50.60% chance of exploitation in the next 30 days, higher than 98.9% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 30-11-2011
   PublishedVulnerability first disclosed.
2. 06-08-2024
   Last modifiedVulnerability information updated.

Description

The mod_proxy module in the Apache HTTP Server 2.0.x through 2.0.64 and 2.2.x before 2.2.18, when the Revision 1179239 patch is in place, does not properly interact with use of (1) RewriteRule and (2) ProxyPassMatch pattern matches for configuration of a reverse proxy, which allows remote attackers to send requests to intranet servers by using the HTTP/0.9 protocol with a malformed URI containing an initial @ (at sign) character. NOTE: this vulnerability exists because of an incomplete fix for CVE-2011-3368.

• CWE-20Improper Input ValidationThe product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.