CVE-2016-4430 in Struts
Summary
by MITRE
Apache Struts 2 2.3.20 through 2.3.28.1 mishandles token validation, which allows remote attackers to conduct cross-site request forgery (CSRF) attacks via unspecified vectors.
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Analysis
by VulDB Data Team • 02/16/2019
Apache Struts 2 versions 2.3.20 through 2.3.28.1 contain a critical vulnerability in their token validation mechanism that fundamentally undermines the framework's cross-site request forgery protection capabilities. This vulnerability resides in the framework's handling of form tokens and session management components, creating a pathway for remote attackers to bypass essential security controls designed to prevent unauthorized requests from being executed on behalf of authenticated users. The flaw manifests when the framework fails to properly validate or enforce token-based authentication mechanisms that should ensure requests originate from legitimate sources within the application's own domain. The unspecified vectors suggest that attackers can exploit this weakness through various attack surfaces within the web application's form processing and session handling logic, making the vulnerability particularly dangerous as it can be leveraged across multiple attack scenarios without specific targeting. This represents a direct violation of the principle of least privilege and fails to maintain proper request integrity validation. The vulnerability maps directly to CWE-352, which specifically addresses Cross-Site Request Forgery, and aligns with ATT&CK technique T1566.001 for initial access through spearphishing attachments and T1566.002 for spearphishing links, as attackers can craft malicious requests that appear legitimate to the application's security controls. The impact of this vulnerability extends beyond simple session hijacking, as successful exploitation allows attackers to perform authenticated actions on behalf of victims, potentially leading to complete account compromise, data manipulation, or unauthorized transactions. Organizations using affected Struts versions face significant risk of unauthorized access to sensitive application functions and user data. The root cause lies in the improper implementation of the token validation process, where the framework fails to maintain consistent enforcement of security tokens across different request handling paths, creating gaps that malicious actors can exploit to bypass the CSRF protection mechanisms. This weakness is particularly concerning in enterprise environments where Struts 2 is commonly used for building web applications with complex user interactions and sensitive business processes. The vulnerability's exploitation requires minimal technical skill and can be automated, making it a preferred target for both targeted attacks and mass exploitation campaigns. Organizations should prioritize immediate patching of affected versions to remediate this vulnerability and restore proper CSRF protection mechanisms within their applications. Security teams must also implement additional monitoring and detection capabilities to identify potential exploitation attempts, as the vulnerability's impact can be subtle and may not immediately manifest in obvious application errors or failed requests. The broader implications include potential compliance violations and increased attack surface for organizations relying on vulnerable Struts 2 applications. Additionally, the vulnerability highlights the critical importance of maintaining up-to-date security frameworks and implementing comprehensive security testing procedures to identify and remediate such flaws before they can be exploited in real-world scenarios.