JBoss InvokerTransformer Remote Code Execution
Description
JBoss application servers using vulnerable versions of the Apache Commons Collections library are susceptible to remote code execution through insecure deserialization. When the application deserializes untrusted data, attackers can exploit the InvokerTransformer class to construct malicious object chains that execute arbitrary commands during the deserialization process. This vulnerability affects JBoss instances that accept serialized Java objects from untrusted sources.
Remediation
Take the following steps to remediate this vulnerability:
1. Immediate Mitigation:
• Apply the latest security patches for JBoss EAP, WildFly, or your specific JBoss product version
• Refer to Red Hat's security advisory for CVE-2015-7501 for version-specific patches
2. Update Commons Collections Library:
• Upgrade Apache Commons Collections to version 3.2.2 or later, or remove it entirely if not required
• Update all application dependencies that may include vulnerable versions
3. Implement Deserialization Controls:
• Configure JEP 290 deserialization filters (Java 9+) or use third-party libraries like SerialKiller for older Java versions
• Implement whitelist-based class filtering to restrict which classes can be deserialized
4. Network-Level Protection:
• Restrict network access to JBoss management interfaces and RMI endpoints
• Deploy Web Application Firewalls (WAF) with rules to detect deserialization attacks
5. Verification:
• Re-scan the application after applying patches to confirm the vulnerability is resolved
• Review application logs for any suspicious deserialization attempts