Apache HTTPD mod_log_config DoS (Feb 10, 2012)
The Apache HTTP server is the most popular HTTP server software in use. It supports a variety of features, many implemented as compiled modules which extend the core functionality. One of the modules, the mod_log_config, provides flexible logging mechanism of client requests.
An HTTP cookie is used for an origin website to send state information to a user’s browser and for the browser to return the state information to the origin site. The state information can be used for authentication, identification of a user session, or anything else that can be accomplished through storing text data on the user’s computer. Cookies are sent in the HTTP Cookie header field as a series of [name]=[value] pairs separated by semicolons. A null-pointer-dereference vulnerability exists in Apache HTTP server’s mod_log_config module. A remote attacker can exploit this vulnerability by continuously sending crafted HTTP requests, which contain Cookie header that lacks both a name and a value. A successful attack could result in a denial-of-service to an Apache HTTP server running mod_log_config. The vulnerability has been assigned as CVE-2012-0021. SonicWALL has released an IPS signature to detect and block specific exploitation attempts targeting this vulnerability. The signature is listed below:- 3432 Suspicious HTTP Cookie Header 5
The SonicWall Capture Labs Threat Research Team gathers, analyzes and vets cross-vector threat information from the SonicWall Capture Threat network, consisting of global devices and resources, including more than 1 million security sensors in nearly 200 countries and territories. The research team identifies, analyzes, and mitigates critical vulnerabilities and malware daily through in-depth research, which drives protection for all SonicWall customers. In addition to safeguarding networks globally, the research team supports the larger threat intelligence community by releasing weekly deep technical analyses of the most critical threats to small businesses, providing critical knowledge that defenders need to protect their networks.
