JBoss Web is the web container, based on Apache Tomcat, in JBoss Enterprise Application Platform. It provides a single deployment platform for the JavaServer Pages (JSP) and Java Servlet technologies.
It was found that when an application used FORM authentication, along with another component that calls request.setUserPrincipal() before the call to FormAuthenticator#authenticate() (such as the Single-Sign-On valve), it was possible to bypass the security constraint checks in the FORM authenticator by appending "/j_security_check" to the end of a URL. A remote attacker with an authenticated session on an affected application could use this flaw to circumvent authorization controls, and thereby access resources not permitted by the roles associated with their authenticated session. (CVE-2012-3546)
Warning: Before applying this update, back up your JBoss Enterprise Application Platform's "server/[PROFILE]/deploy/" directory, along with all other customized configuration files.
Users of JBoss Enterprise Application Platform 4.3.0 CP10 on Red Hat Enterprise Linux 4 and 5 should upgrade to these updated packages, which correct this issue. The JBoss server process must be restarted for this update to take effect.