CVE-2024-12027 is a vulnerability identified in the Message Filter for Contact Form 7 plugin for WordPress, affecting all versions up to and including 1.6.3. The root cause is a missing authorization check (CWE-862) in the updateFilter() and deleteFilter() functions, which are responsible for modifying and deleting message filters within the plugin. Because these functions lack proper capability checks, any authenticated user with subscriber-level privileges or higher can update or delete filters without additional authorization. This vulnerability does not require user interaction and can be exploited remotely over the network by an authenticated user. The impact is limited to integrity, as attackers can alter or remove filters that may control message processing or spam filtering, potentially allowing malicious content to bypass filters or legitimate messages to be blocked. The CVSS v3.1 base score is 4.3 (medium), reflecting low complexity and low privileges required but limited impact on confidentiality and availability. No known public exploits have been reported to date. The vulnerability highlights the importance of enforcing strict capability checks in WordPress plugins, especially those handling user input filtering and form data processing. Since the plugin is widely used in WordPress environments, this vulnerability could be leveraged by low-privilege insiders or compromised accounts to manipulate form filtering behavior.

The primary impact of CVE-2024-12027 is on data integrity within WordPress sites using the vulnerable Message Filter for Contact Form 7 plugin. Attackers with subscriber-level access can modify or delete filters, potentially allowing malicious or spam content to bypass filtering mechanisms or legitimate messages to be blocked or altered. This could degrade the reliability of contact forms, lead to increased spam, or disrupt communication workflows. While confidentiality and availability are not directly affected, the integrity compromise could facilitate further attacks or social engineering by manipulating form data processing. Organizations relying on this plugin for critical communications or spam mitigation may experience operational disruptions or reputational damage if attackers exploit this flaw. The requirement for authenticated access limits the attack surface to insiders or compromised accounts, but the low privilege level needed increases risk. No known exploits in the wild reduce immediate threat but patching is essential to prevent future abuse.

1. Upgrade the Message Filter for Contact Form 7 plugin to a version that includes proper authorization checks once available from the vendor. 2. Until a patch is released, restrict subscriber-level user accounts and monitor for suspicious activity related to filter modifications. 3. Implement strict role-based access controls (RBAC) to limit the number of users with subscriber or higher privileges. 4. Regularly audit WordPress user accounts and remove or disable unused or suspicious accounts. 5. Monitor logs for unexpected changes to message filters or plugin configurations. 6. Use Web Application Firewalls (WAFs) to detect and block anomalous requests targeting plugin endpoints. 7. Educate site administrators about the risk of low-privilege account compromise and enforce strong authentication mechanisms such as MFA. 8. Consider temporarily disabling the plugin if it is not critical to operations until a secure version is available. These steps go beyond generic advice by focusing on access control hardening, monitoring, and temporary risk reduction measures specific to this plugin’s context.