JBoss Seam framework remote code execution
Description
The JBoss Seam Framework is a Java-based application framework for building web applications. Versions prior to the security patch contain an input validation vulnerability in the processing of JBoss Expression Language (EL) expressions. Attackers can inject malicious EL expressions through URL parameters, which are then evaluated by the server without proper sanitization. This allows remote attackers to execute arbitrary Java code by crafting specially-formatted expressions and appending them to URLs of vulnerable JBoss Seam applications.
Remediation
Immediately upgrade to a patched version of the JBoss Seam framework. For Red Hat Enterprise Linux systems, apply the jboss-seam2 security update (RHSA-2010:0564) using your package manager. For other deployments, upgrade to JBoss Seam 2.2.1 or later. As an interim mitigation measure, implement input validation and sanitization for all URL parameters before they are processed by the application, and consider deploying a web application firewall (WAF) with rules to detect and block malicious EL expressions. Review application logs for suspicious URL patterns containing EL syntax such as '${' or '#{' in parameters to identify potential exploitation attempts.