/hvaonline/posts/list/13.html JForum - http://www.jforum.net Apache2 mod_proxy_balancer CSRF, XSS, Memory Corruption and DoS Vulnerability ------------------------------------------------------------------------ SUMMARY The Apache HTTP Server Project is "an effort to develop and maintain an open-source HTTP server for modern operating systems including UNIX and Windows NT. The goal of this project is to provide a secure, efficient and extensible server that provides HTTP services in sync with the current HTTP standards. Apache has been the most popular web server on the Internet since April 1996. The November 2005 Netcraft Web Server Survey found that more than 70% of the web sites on the Internet are using Apache, thus making it more widely used than all other web servers combined". http://httpd.apache.org/docs/2.2/mod/mod_proxy_balancer.html mod_proxy_balancer manager "enables dynamic update of balancer members. You can use balancer manager to change the balance factor or a particular member, or put it in the off line mode". Multiple vulnerabilities have been discovered in Apache2's mod_proxy_balancer management interface. DETAILS Vulnerable Systems: * Apache version 2.2.x with mod_proxy_balancer Immune Systems: * Apache version 2.2.27-dev with mod_proxy_balancer Apache2 Cross-Site Request Forgery (CSRF) Vulnerability Due to the fact that all actions are performed by GET method there exist "CSRF". The balancer-manager should use POST for requests which have side-effects which would significantly mitigate the "CSRF" issue. Apache2 HTML Injection (XSS) Vulnerability First XSS The HTML Injection (XSS) vulnerability exist in "mod_proxy_balancer.c". By Enabling Balancer Manager Support we can trigger XSS vulnerability. Input passed to the: "ss" - called ""StickySession Identifier", "wr" - called "Route", "rr" - called "Route Redirect", parameters in balancer-manager are not properly sanitized leading to execute arbitrary HTML and script code in a victim's browser. Second XSS Input passed in the URL to "balancer-manager" is not properly sanitized leading to execute arbitrary HTML and script code in a victim's browser. Apache2 Denial of Service Vulnerability The Denial of Service is caused due to an error in the "balancer_handler()" function that manages the loadfactors and member status. When attacker input invalid "bb" variable while editing worker settings leads to "Denial of Service Vulnerability". Apache2 Memory Corruption The Memory corruption is caused due to an error in the "mod_proxy_balancer" when attacker input in the URL 7390 or 7506 or 7622 "A" chars. CVE Information: http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2007-6420 http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2007-6421 http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2007-6422 http://www.cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2007-6423 ADDITIONAL INFORMATION The information has been provided by <mailto:sp3x@securityreason.com> sp3x. The original article can be found at: http://securityreason.com/achievement_securityalert/48]]> /hvaonline/posts/list/18495.html#110385 /hvaonline/posts/list/18495.html#110385 GMT