CVE-2021-4380 in Pinterest Automatic Plugin
Summary
by MITRE • 06/07/2023
The Pinterest Automatic plugin for WordPress is vulnerable to authorization bypass due to missing capability checks on the 'wp_pinterest_automatic_parse_request' function and the 'process_form.php' script in versions up to, and including, 1.14.3. This makes it possible for unauthenticated attackers to update arbitrary options on a site that can be used to create new administrative user accounts or redirect unsuspecting site visitors.
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Analysis
by VulDB Data Team • 04/09/2026
The vulnerability identified as CVE-2021-4380 affects the Pinterest Automatic plugin for WordPress, specifically targeting versions up to and including 1.14.3. This authorization bypass flaw stems from inadequate capability validation within the plugin's core functionality, creating a significant security risk for WordPress installations that utilize this particular plugin. The vulnerability manifests through two primary attack vectors: the 'wp_pinterest_automatic_parse_request' function and the 'process_form.php' script, both of which fail to properly verify user permissions before executing sensitive operations.
The technical implementation of this vulnerability resides in the absence of proper capability checks that should normally validate whether an authenticated user possesses sufficient privileges to perform administrative actions. According to CWE-863, this represents a weakness where an actor is able to access a resource or perform an operation for which they are not authorized. The flaw allows unauthenticated attackers to exploit the plugin's functionality to manipulate WordPress options, effectively bypassing the standard WordPress authorization mechanisms that typically require users to be logged in with appropriate administrative privileges. This misconfiguration creates a path for attackers to execute arbitrary code or modify critical system parameters without proper authentication.
The operational impact of this vulnerability extends beyond simple unauthorized access, as it enables attackers to create new administrative user accounts within the compromised WordPress environment. This capability directly aligns with ATT&CK technique T1133, which describes persistence through external remote services, and T1078, which covers valid accounts as a means of gaining access. Additionally, the vulnerability allows for redirection of unsuspecting site visitors, creating potential for phishing attacks or malicious traffic redirection that can compromise user trust and security. The ability to manipulate site options provides attackers with a comprehensive attack surface that can lead to full system compromise.
Mitigation strategies for this vulnerability should prioritize immediate plugin updates to versions that address the authorization bypass issue, as the vendor has likely released patches to implement proper capability checks. Organizations should also implement network-level monitoring to detect unusual patterns in plugin API calls and option modifications. The remediation process should include thorough security auditing of all installed WordPress plugins to identify similar authorization bypass vulnerabilities. According to the OWASP Top Ten 2021, this type of vulnerability falls under the category of "Insecure Design" and should be addressed through proper input validation and capability verification mechanisms. Additionally, implementing role-based access controls and regular security assessments can help prevent similar issues from emerging in other plugin components or custom WordPress functionality.