CVE-2021-36543 in SeedDMS
Summary
by MITRE • 08/03/2021
Cross-Site Request Forgery (CSRF) vulnerability in the /op/op.UnlockDocument.php in SeedDMS v5.1.x
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Analysis
by VulDB Data Team • 08/07/2021
The CVE-2021-36543 vulnerability represents a critical cross-site request forgery flaw located within the SeedDMS document management system version 5.1.x. This vulnerability specifically affects the /op/op.UnlockDocument.php endpoint, which handles document unlocking operations within the web application. The flaw resides in the application's insufficient validation of incoming requests, failing to properly verify the authenticity of user intentions when performing document unlocking actions. SeedDMS is a widely deployed open-source document management system that serves organizations requiring centralized document storage and access control, making this vulnerability particularly concerning for enterprise environments.
The technical implementation of this CSRF vulnerability stems from the absence of proper anti-forgery tokens or request origin validation mechanisms within the document unlocking functionality. When a user accesses the /op/op.UnlockDocument.php endpoint, the application should verify that the request originates from a legitimate authenticated session and contains proper authorization credentials. However, the current implementation accepts unlock requests without adequate verification of the request source or user intent. This allows attackers to craft malicious web pages or phishing campaigns that can automatically submit unlock requests to the vulnerable application on behalf of authenticated users. The vulnerability operates under CWE-352, which specifically addresses cross-site request forgery conditions where applications fail to validate request origins and user authorization.
The operational impact of this vulnerability extends beyond simple document access manipulation, as it can potentially lead to unauthorized document modifications, data exposure, and disruption of business processes. An attacker who successfully exploits this vulnerability could unlock documents that are protected by access controls, potentially allowing unauthorized individuals to access sensitive information. The attack surface is particularly wide given that SeedDMS is deployed in various enterprise environments where document security and access control are paramount. This vulnerability directly violates the principle of least privilege and can be categorized under the ATT&CK technique T1566 for credential access through social engineering. The exploitation typically requires a victim to be authenticated to the SeedDMS system, making it a session-based attack that leverages the trust relationship between the user and the web application.
Mitigation strategies for CVE-2021-36543 should focus on implementing robust anti-forgery token mechanisms throughout the application's request handling process. The most effective approach involves generating unique, unpredictable tokens for each user session and requiring their inclusion in all state-changing operations including document unlocking. Organizations should also implement proper referer header validation and consider implementing Content Security Policy headers to limit the scope of potential exploitation. Additionally, the application should enforce strict session management controls and implement automatic session timeout mechanisms to minimize the window of opportunity for attackers. Security patches should be applied immediately to all affected versions of SeedDMS, as the vulnerability has been identified and documented in multiple security advisories. Network segmentation and monitoring should be implemented to detect suspicious activities related to document unlocking operations, and regular security assessments should be conducted to identify similar vulnerabilities in other application components. The fix should align with OWASP Top Ten security practices and follow established secure coding guidelines to prevent similar issues in future development cycles.