CVE-2025-31780 Overview
CVE-2025-31780 is a Missing Authorization vulnerability [CWE-862] affecting the Andy Stratton Append Content WordPress plugin. The flaw exists in versions up to and including 2.1.1 and stems from incorrectly configured access control on plugin functionality. Unauthenticated attackers can reach protected actions over the network without user interaction. The advisory published by Patchstack describes the issue as a Cross-Site Request Forgery (CSRF) to settings-change condition, resulting in limited integrity and availability impact on affected WordPress installations.
Critical Impact
Unauthenticated network-based attackers can modify plugin settings on affected WordPress sites running Append Content <= 2.1.1, altering site content or configuration without authorization.
Affected Products
- Andy Stratton Append Content WordPress plugin
- Append Content versions from n/a through 2.1.1
- WordPress sites with the vulnerable plugin installed and activated
Discovery Timeline
- 2025-04-01 - CVE-2025-31780 published to the National Vulnerability Database (NVD)
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-31780
Vulnerability Analysis
The Append Content plugin fails to enforce authorization checks on functionality that modifies plugin settings. The Patchstack advisory classifies the root condition as a CSRF-to-settings-change issue, where the plugin does not validate that the requester holds the required capability or a valid nonce before applying changes. Because the request executes in the context of an authenticated administrator when a victim visits an attacker-controlled page, or in some cases without valid authentication at all, the access control decision is bypassed.
The vulnerability falls under Missing Authorization [CWE-862]. It affects the confidentiality boundary minimally but permits attacker-controlled modification of stored plugin settings. Sites running Append Content <= 2.1.1 process attacker-driven configuration writes, which can be used to alter content that the plugin appends to posts or pages.
Root Cause
The root cause is the absence of a capability check and nonce validation on the settings-handling code path in Append Content <= 2.1.1. WordPress plugins are expected to gate privileged actions using current_user_can() and to validate requests with wp_verify_nonce() or check_admin_referer(). The affected plugin does not enforce these controls consistently on the settings update handler.
Attack Vector
An attacker delivers a crafted request, typically embedded in a malicious page or link, that targets the plugin's settings endpoint on a vulnerable WordPress site. When an authenticated administrator visits the attacker's page, the browser issues the request under the admin session, and the plugin applies the settings change without validating intent or authorization. The attack requires no elevated privileges from the attacker and no direct user interaction beyond visiting an attacker-controlled resource.
See the Patchstack WordPress Vulnerability Report for technical details.
Detection Methods for CVE-2025-31780
Indicators of Compromise
- Unexpected modifications to Append Content plugin settings stored in the wp_options table
- Inbound HTTP POST requests to plugin admin endpoints originating from external referrers
- Content changes appearing on posts or pages served by the Append Content plugin without a corresponding admin action in the WordPress audit trail
Detection Strategies
- Inventory WordPress installations and identify sites running Append Content at version 2.1.1 or earlier
- Review web server access logs for POST requests to wp-admin/admin.php or admin-post.php targeting Append Content actions, particularly with off-site Referer headers
- Compare current plugin settings against known-good baselines to identify unauthorized changes
Monitoring Recommendations
- Enable WordPress audit logging to record plugin settings changes and administrator actions
- Monitor for anomalous administrator session activity, including requests generated shortly after admins visit external links
- Alert on modifications to plugin option rows in the database that occur outside change-management windows
How to Mitigate CVE-2025-31780
Immediate Actions Required
- Identify all WordPress sites running the Append Content plugin at version 2.1.1 or earlier
- Deactivate and remove the Append Content plugin until a vendor-supplied fix is confirmed available
- Restrict access to wp-admin by IP allowlist where operationally feasible
- Review plugin settings and post content for unauthorized changes and restore from backup if tampering is detected
Patch Information
At the time of publication, the NVD entry for CVE-2025-31780 lists affected versions from n/a through <= 2.1.1. Administrators should consult the Patchstack WordPress Vulnerability Report for the latest patch status and upgrade guidance from the plugin author.
Workarounds
- Remove or deactivate the Append Content plugin until a patched version is confirmed available
- Enforce administrator session hygiene by requiring administrators to log out of WordPress when not actively managing the site
- Deploy a Web Application Firewall (WAF) rule to block cross-origin POST requests to plugin admin endpoints lacking a valid same-origin Referer
- Apply least-privilege principles so that only users requiring plugin configuration access hold administrator capabilities
# Configuration example: WordPress WP-CLI commands to identify and remove the vulnerable plugin
wp plugin list --name=append-content --fields=name,status,version
wp plugin deactivate append-content
wp plugin uninstall append-content
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
