CVE-2023-0876 in WP Meta SEO Plugin
Summary
by MITRE • 03/20/2023
The WP Meta SEO WordPress plugin before 4.5.3 does not authorize several ajax actions, allowing low-privilege users to make updates to certain data and leading to an arbitrary redirect vulnerability.
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Analysis
by VulDB Data Team • 04/12/2023
The WP Meta SEO WordPress plugin vulnerability CVE-2023-0876 represents a critical authorization flaw that affects versions prior to 453. This vulnerability resides within the plugin's handling of ajax actions, specifically failing to properly validate user permissions before executing sensitive operations. The flaw allows attackers with low privilege accounts to exploit the system and manipulate data that should be restricted to administrators or higher-privileged users. The vulnerability manifests through unauthorized access to administrative functions that are typically protected by proper authentication checks, creating a pathway for privilege escalation and unauthorized modifications to the website's metadata configuration.
The technical implementation of this vulnerability stems from inadequate input validation and access control mechanisms within the plugin's ajax endpoint handlers. When legitimate users attempt to perform administrative actions through ajax calls, the system fails to verify whether the requesting user possesses sufficient privileges to execute these operations. This authorization bypass enables malicious actors to craft specific requests that trigger unauthorized updates to the plugin's configuration data. The vulnerability is particularly concerning because it operates at the application layer, leveraging the existing trust relationship between the WordPress platform and its plugins without proper security boundaries. The flaw aligns with CWE-285, which addresses improper authorization in software systems, and demonstrates how insufficient access control checks can create significant security risks.
The operational impact of CVE-2023-0876 extends beyond simple data modification to include potential arbitrary redirect capabilities that can be leveraged for phishing attacks or malicious redirection campaigns. When low-privilege users can manipulate plugin configurations, they may inadvertently or intentionally introduce malicious redirects that could compromise user data or direct visitors to harmful websites. This vulnerability creates an attack surface that could be exploited by attackers who gain access through social engineering, credential theft, or other initial compromise methods. The arbitrary redirect functionality provides an additional vector for delivering malware or conducting credential harvesting attacks, making this vulnerability particularly dangerous in environments where user trust is paramount. The security implications align with ATT&CK technique T1071.004, which covers application layer protocol tunneling, and T1566, which addresses credential harvesting through social engineering.
Mitigation strategies for CVE-2023-0876 require immediate action to upgrade to WP Meta SEO version 4.5.3 or later, which contains the necessary authorization fixes. System administrators should conduct thorough security audits of their WordPress installations to identify any other plugins that may exhibit similar authorization flaws. The vulnerability highlights the importance of implementing proper input validation and access control checks throughout the application lifecycle, particularly for ajax endpoints that handle sensitive operations. Organizations should also consider implementing network-level monitoring to detect anomalous ajax requests that may indicate exploitation attempts. Security teams should review their incident response procedures to ensure rapid identification and remediation of similar authorization bypass vulnerabilities. Regular security assessments of WordPress plugins and themes remain essential for maintaining secure web environments, as this vulnerability demonstrates how seemingly minor authorization gaps can create substantial security risks. The fix implemented in version 4.5.3 addresses the root cause by strengthening the permission checking mechanisms for ajax actions, ensuring that only properly authenticated users with appropriate privileges can execute administrative functions within the plugin.