CVE-2021-36876 in uListing Plugin
Summary
by MITRE • 09/28/2021
Multiple Cross-Site Request Forgery (CSRF) vulnerabilities in WordPress uListing plugin (versions
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Analysis
by VulDB Data Team • 10/03/2021
The CVE-2021-36876 vulnerability represents a critical security flaw in the WordPress uListing plugin that exposes websites to multiple cross-site request forgery attacks. This vulnerability affects multiple versions of the uListing plugin and demonstrates a fundamental weakness in the plugin's handling of user authentication and request validation mechanisms. The flaw allows attackers to execute unauthorized actions on behalf of authenticated users without their knowledge or consent, potentially leading to complete compromise of affected WordPress installations.
The technical implementation of this CSRF vulnerability stems from the plugin's failure to properly validate and verify the origin of HTTP requests. Specifically, the uListing plugin does not adequately implement anti-CSRF tokens or proper referer header checks in its administrative functions. This absence creates a pathway for malicious actors to craft specially crafted requests that appear legitimate to the WordPress backend system. The vulnerability manifests when authenticated users visit malicious websites or click on compromised links that trigger unauthorized actions within the uListing plugin's administrative interface. Attackers can leverage this weakness to modify listings, delete content, or potentially escalate privileges within the WordPress environment.
The operational impact of CVE-2021-36876 extends beyond simple data manipulation, as it can lead to complete system compromise when combined with other exploitation techniques. An attacker who successfully exploits this vulnerability can perform actions such as creating new user accounts, modifying existing listings, deleting critical content, or even installing malicious plugins. The vulnerability is particularly dangerous because it requires no authentication from the attacker's perspective once a victim is logged into the WordPress admin interface. This makes it a prime target for social engineering attacks where users are tricked into visiting malicious websites while authenticated. The attack vector typically involves sending crafted HTTP requests that exploit the plugin's lack of proper CSRF protection mechanisms.
Security professionals should immediately implement mitigations including updating to patched versions of the uListing plugin, implementing proper CSRF token validation, and monitoring for suspicious administrative activities. The vulnerability aligns with CWE-352, which specifically addresses cross-site request forgery weaknesses in web applications. From an ATT&CK framework perspective, this vulnerability maps to T1078 for valid accounts and T1547 for privilege escalation through compromised administrative interfaces. Organizations should also consider implementing web application firewalls to detect and block suspicious request patterns, while conducting thorough security audits of all installed plugins to identify similar vulnerabilities. Regular security testing and vulnerability scanning should be implemented to ensure early detection of similar CSRF flaws in other components of the WordPress ecosystem. The remediation process must include not only updating the vulnerable plugin but also reviewing and strengthening the overall security posture of WordPress installations to prevent similar issues in other components of the web application stack.