CVE-2025-54053 Overview
CVE-2025-54053 is a PHP Object Injection vulnerability in the Groundhogg WordPress plugin developed by Adrian Tobey. The flaw stems from unsafe deserialization of untrusted data [CWE-502] and affects all versions of Groundhogg up to and including 4.2.2. An authenticated attacker with high privileges can supply crafted serialized input to trigger object instantiation within the plugin's execution context. Successful exploitation can compromise confidentiality, integrity, and availability of the affected WordPress site.
Critical Impact
Authenticated attackers can inject PHP objects that may lead to arbitrary code execution, data tampering, or complete site compromise when suitable gadget chains exist in the WordPress environment.
Affected Products
- Adrian Tobey Groundhogg plugin for WordPress
- All versions from initial release through 4.2.2
- WordPress sites with the vulnerable Groundhogg plugin installed and activated
Discovery Timeline
- 2025-08-20 - CVE CVE-2025-54053 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-54053
Vulnerability Analysis
The Groundhogg plugin processes serialized PHP data without adequately validating or restricting the classes that can be instantiated. When attacker-controlled input reaches a unserialize() call, PHP reconstructs arbitrary objects and invokes their magic methods such as __wakeup() or __destruct(). Attackers can chain these methods with existing classes loaded by WordPress, other plugins, or the Groundhogg codebase to achieve unintended actions. The impact depends on the gadget chains available in the target environment but can extend to file writes, SQL execution, or remote code execution.
Root Cause
The root cause is unsafe deserialization of untrusted data [CWE-502]. The plugin does not sanitize or reject serialized payloads before passing them to PHP's deserialization routines, allowing object injection.
Attack Vector
Exploitation requires network access to the WordPress site and an authenticated account with high privileges. The attacker submits a crafted serialized payload through a Groundhogg endpoint that ultimately calls unserialize(). The high attack complexity reflects the need to identify a viable gadget chain within the target's plugin and theme stack. Details of the vulnerable sink are documented in the Patchstack WordPress Vulnerability Advisory.
Detection Methods for CVE-2025-54053
Indicators of Compromise
- Presence of Groundhogg plugin versions 4.2.2 or earlier in the WordPress plugin directory.
- Web server logs containing serialized PHP patterns such as O: or a: followed by class names within Groundhogg request parameters.
- Unexpected PHP files, scheduled tasks, or admin users created shortly after authenticated Groundhogg activity.
Detection Strategies
- Inspect HTTP request bodies and query parameters sent to Groundhogg endpoints for serialized object signatures.
- Review WordPress audit logs for high-privilege account activity coinciding with anomalous plugin requests.
- Correlate outbound network connections initiated by the PHP worker process with recent Groundhogg API calls.
Monitoring Recommendations
- Enable verbose logging in the web application firewall for requests targeting Groundhogg URLs.
- Alert on any modification to core WordPress files or the wp-content/uploads directory following authenticated sessions.
- Track privilege changes and new administrator accounts within the WordPress user table.
How to Mitigate CVE-2025-54053
Immediate Actions Required
- Update Groundhogg to a version later than 4.2.2 once the vendor publishes a fixed release.
- Rotate credentials for all high-privilege WordPress accounts on affected sites.
- Audit installed plugins and themes for known gadget chains that could amplify object injection impact.
Patch Information
Refer to the Patchstack WordPress Vulnerability Advisory for the current patched version and vendor guidance. Apply the fix through the WordPress plugin updater or by replacing the plugin directory with the patched release.
Workarounds
- Deactivate and remove the Groundhogg plugin until a patched version is deployed.
- Restrict access to the WordPress admin interface using IP allow lists or VPN gating.
- Deploy a web application firewall rule that blocks serialized PHP object patterns in requests to Groundhogg endpoints.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
