CVE-2013-1965 in Struts
Summary
by MITRE
Apache Struts Showcase App 2.0.0 through 2.3.13, as used in Struts 2 before 2.3.14.1, allows remote attackers to execute arbitrary OGNL code via a crafted parameter name that is not properly handled when invoking a redirect.
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Analysis
by VulDB Data Team • 12/27/2024
The vulnerability identified as CVE-2013-1965 represents a critical remote code execution flaw within the Apache Struts framework that affected versions 2.0.0 through 2.3.13. This vulnerability specifically targets the Showcase Application component of Struts 2 before version 2.3.14.1, creating a pathway for malicious actors to execute arbitrary code on affected systems. The flaw resides in the improper handling of parameter names during redirect operations, which creates a dangerous condition where user-supplied input can be interpreted as executable code rather than benign data. This vulnerability directly impacts the core security model of the framework by allowing attackers to bypass normal input validation mechanisms and inject malicious OGNL expressions that get evaluated by the system. The vulnerability is classified under CWE-94, which describes "Improper Control of Generation of Code ('Code Injection')" and aligns with ATT&CK technique T1059.001 for command and scripting interpreter. The affected versions of Apache Struts 2 were widely deployed across enterprise environments, making this vulnerability particularly dangerous as it could be exploited to compromise web applications that relied on the framework for their functionality.
The technical exploitation of this vulnerability occurs when an attacker crafts a malicious parameter name that contains OGNL (Object-Graph Navigation Language) expressions. During the redirect process, the framework fails to properly sanitize or escape these parameter names, allowing the OGNL expressions to be evaluated as code within the application context. This occurs because the redirect mechanism in Struts 2 does not adequately validate or neutralize potentially dangerous input before processing it through the OGNL expression evaluator. The vulnerability leverages the framework's default behavior of automatically evaluating parameter values as OGNL expressions, which is intended for legitimate use cases but becomes exploitable when malicious input is present. Attackers can construct parameter names that contain payloads such as #_request.get("cmd").exec(#_request.get("cmd")) which would execute arbitrary system commands on the server. This flaw demonstrates a classic case of insufficient input validation and improper output encoding, where the framework's trust in parameter names leads to code execution. The vulnerability is particularly dangerous because it operates at the framework level rather than the application level, meaning that any application built on the affected Struts versions could be compromised, regardless of the specific application logic implemented by developers.
The operational impact of CVE-2013-1965 extends far beyond simple remote code execution, as it provides attackers with complete control over affected systems. Successful exploitation allows threat actors to execute arbitrary commands, access sensitive data, establish persistent backdoors, and potentially move laterally within network environments. The vulnerability affects organizations that deployed Struts 2 applications without proper patching or mitigation strategies, creating a significant risk for web applications handling sensitive information. Organizations using the affected versions faced potential data breaches, system compromise, and compliance violations, as the vulnerability could be exploited without requiring authentication or specific user interaction. The widespread adoption of Apache Struts 2 across enterprise applications meant that numerous organizations were potentially exposed, with the vulnerability being actively exploited in the wild. This type of vulnerability directly impacts the CIA triad by compromising confidentiality, integrity, and availability of affected systems. The vulnerability also demonstrates the importance of proper input validation and the principle of least privilege in web application security, as the flaw could be exploited through simple HTTP parameter manipulation.
Organizations should immediately implement mitigation strategies including updating to Apache Struts 2 version 2.3.14.1 or later, which contains the necessary patches to address the vulnerability. Additionally, implementing proper input validation at the application level can provide additional defense in depth, ensuring that parameter names are properly sanitized before being processed. Network-level mitigations such as web application firewalls and intrusion detection systems can help detect and block exploitation attempts, though these should not be relied upon as the primary defense mechanism. Security teams should also conduct comprehensive vulnerability assessments to identify all applications running affected versions of Struts 2 and ensure proper patch management processes are in place. The vulnerability highlights the importance of monitoring for known exploits in the wild and maintaining up-to-date security intelligence feeds. Organizations should also review their application architecture to minimize the attack surface and implement proper security controls such as input filtering, output encoding, and proper error handling to reduce the risk of similar vulnerabilities. Regular security testing and code reviews should be conducted to identify potential injection points and ensure that frameworks are properly configured to prevent unintended code execution. The remediation process should include not only patching but also comprehensive testing to ensure that the fixes do not introduce regressions in application functionality while maintaining the security posture of the affected systems.