Red Hat JBoss Seam 2 Expression Language (EL) Injection Remote Code Execution Vulnerability (CVE-2010-1871)

1. Vulnerability Overview & Root Cause

This vulnerability (CVE-2010-1871) exists in the JBoss Seam 2 framework due to insufficient sanitization of user-supplied inputs before passing them to the JBoss Expression Language (EL) engine. When the Java Security Manager is not properly configured, these inputs are evaluated as active EL expressions, allowing arbitrary object graph navigation and method invocation.

2. Exploitation Mechanics & Attack Scenario

An attacker crafts a malicious HTTP request containing EL syntax (e.g., #{...}) within URL parameters or paths. Because the application fails to sanitize this input, the Seam framework passes it directly to the EL parser. By leveraging Java reflection within the EL payload, the attacker can access sensitive classes such as java.lang.Runtime to execute arbitrary operating system commands on the host.

3. Infrastructure & Business Impact

With a CVSS 3.1 score of 8.8 (High) and its inclusion in the CISA KEV catalog, this vulnerability poses a severe threat. Successful exploitation grants the attacker the execution privileges of the application server process, potentially leading to full system compromise, lateral movement within the internal network, and data exfiltration.