CVE-2011-4317: Input Validation
Additional problems were discovered in the httpd fix for CVE-2011-3368 - a reverse proxy bypass flaw - tracked via bug #740045. Upstream mailing list post identifies following request forms, which are not handled correctly:
GET @localhost::8880 HTTP/1.0\r\n\r\n GET qualys:@qqq.qq.qualys.com HTTP/1.0\r\n\r\n
Reference: http://thread.gmane.org/gmane.comp.apache.devel/46440
Other sources
The modproxy module in the Apache HTTP Server 1.3.x through 1.3.42, 2.0.x through 2.0.64, and 2.2.x through 2.2.21, 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 via a malformed URI containing an @ (at sign) character and a : (colon) character in invalid positions. NOTE: this vulnerability exists because of an incomplete fix for CVE-2011-3368.
— MITRE
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2011-4317?
CVE-2011-4317 is considered a high severity vulnerability due to its potential for exploitation in reverse proxy configurations.
How do I fix CVE-2011-4317?
To fix CVE-2011-4317, upgrade to a patched version of the Apache HTTP server that addresses this vulnerability.
What versions are affected by CVE-2011-4317?
CVE-2011-4317 affects multiple versions of the Apache HTTP server including 1.3.x and 2.2.22.
What kind of attack can exploit CVE-2011-4317?
CVE-2011-4317 can be exploited to perform reverse proxy bypass attacks, leading to unauthorized access.
Are there any known exploits for CVE-2011-4317?
Yes, there are known exploits for CVE-2011-4317 that leverage the reverse proxy bypass vulnerability.