CVE-2024-9891 in Multiline Files Upload for Contact Form 7
Summary
by MITRE • 10/16/2024
The Multiline files upload for contact form 7 plugin for WordPress is vulnerable to unauthorized plugin deactivation due to a missing capability check on the mfcf7_zl_custom_handle_deactivation_plugin_form_submission() function in all versions up to, and including, 2.8.1. This makes it possible for authenticated attackers, with Subscriber-level access and above, to deactivate the plugin and send a custom reason from the site.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 10/16/2024
The vulnerability identified as CVE-2024-9891 affects the Multiline files upload for contact form 7 plugin for WordPress, specifically targeting versions up to and including 2.8.1. This security flaw resides in the mfcf7_zl_custom_handle_deactivation_plugin_form_submission() function where a critical capability check is missing. The vulnerability represents a privilege escalation issue that allows authenticated users with Subscriber-level access or higher to perform actions typically restricted to administrators. The absence of proper access control validation creates an avenue for unauthorized plugin deactivation, which can significantly impact the functionality and security posture of WordPress installations relying on this plugin.
The technical implementation of this vulnerability stems from inadequate input validation and access control mechanisms within the plugin's codebase. When an authenticated user submits a form that triggers the deactivation function, the system fails to verify whether the user possesses sufficient privileges to perform this operation. This missing capability check creates a direct path for privilege escalation, as users at the Subscriber level can leverage this flaw to manipulate plugin states. The vulnerability is classified under CWE-284, which specifically addresses inadequate access control, and aligns with ATT&CK technique T1078.004 related to valid accounts and T1566.002 for spearphishing with links, as attackers can exploit this weakness to gain unauthorized control over plugin functionality.
The operational impact of this vulnerability extends beyond simple plugin deactivation, as it can lead to significant disruptions in website functionality and potential security degradation. When an attacker deactivates the plugin, they can effectively remove critical contact form functionality from the website, potentially disrupting legitimate user interactions and data collection processes. Additionally, the ability to send custom reasons from the site provides attackers with an opportunity to obfuscate their malicious activities and potentially confuse system administrators during incident response efforts. This vulnerability can be particularly damaging in environments where the contact form plugin serves as a critical component of business operations, as it can lead to service interruptions and data loss.
Mitigation strategies for this vulnerability should focus on immediate patching and access control reinforcement. Administrators should upgrade to the latest version of the Multiline files upload for contact form 7 plugin where the missing capability check has been implemented. In the interim, organizations should consider implementing additional access controls through WordPress user role management, ensuring that users with Subscriber-level access do not have unnecessary permissions to modify plugin states. Network-level monitoring should be enhanced to detect unusual plugin deactivation patterns, and regular security audits should be conducted to identify similar access control gaps in other installed plugins. The remediation process should also include reviewing all plugin functions that handle administrative operations to ensure proper capability validation is implemented throughout the WordPress ecosystem.