CVE-2023-6598 in SpeedyCache Plugin
Summary
by MITRE • 01/11/2024
The SpeedyCache plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on the speedycache_save_varniship, speedycache_img_update_settings, speedycache_preloading_add_settings, and speedycache_preloading_delete_resource functions in all versions up to, and including, 1.1.3. This makes it possible for authenticated attackers, with subscriber-level access and above, to update plugin options.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 04/11/2026
The SpeedyCache WordPress plugin vulnerability represents a critical authorization flaw that undermines the security model of the affected system. This vulnerability exists within the plugin's core functionality where multiple administrative functions lack proper capability checks, creating a pathway for unauthorized data modification. The flaw affects all versions up to and including 1.1.3, making it a widespread concern across numerous installations. The vulnerability specifically targets four key functions: speedycache_save_varniship, speedycache_img_update_settings, speedycache_preloading_add_settings, and speedycache_preloading_delete_resource, each of which handles critical plugin configuration and operational parameters.
The technical nature of this vulnerability stems from the absence of proper access control validation within the plugin's codebase. When authenticated users with subscriber-level privileges attempt to interact with these functions, the system fails to verify whether the user possesses the necessary administrative permissions. This missing capability check creates a privilege escalation vector where low-privilege users can manipulate core plugin settings that should only be accessible to administrators or users with elevated privileges. The flaw operates at the application layer, specifically within the WordPress plugin architecture where user permissions are not properly enforced for administrative operations.
The operational impact of this vulnerability extends beyond simple data modification, potentially enabling attackers to compromise the entire caching infrastructure of affected WordPress sites. An attacker with subscriber-level access can alter varnish IP configurations, modify image optimization settings, adjust preloading behaviors, and delete critical resources, all of which can significantly impact site performance, security posture, and user experience. This vulnerability aligns with CWE-284, which describes improper access control mechanisms, and represents a clear violation of the principle of least privilege. The consequences can range from performance degradation through misconfigured caching to potential security breaches that could be leveraged for further attacks.
Organizations using the SpeedyCache plugin must implement immediate mitigations to protect their WordPress installations from exploitation. The primary recommendation involves upgrading to the latest available version of the plugin where the capability checks have been properly implemented. Additionally, administrators should review user permissions and consider implementing role-based access controls that limit the capabilities of low-privilege users. Network monitoring should be enhanced to detect unusual patterns of plugin configuration changes that might indicate exploitation attempts. The vulnerability also highlights the importance of regular security audits and proper input validation in WordPress plugin development, aligning with ATT&CK technique T1078 for valid accounts and T1566 for credential harvesting through compromised accounts. Organizations should also consider implementing web application firewalls and security monitoring solutions that can detect and prevent exploitation attempts targeting known WordPress vulnerabilities.