CVE-2025-28940 Overview
CVE-2025-28940 is a Cross-Site Request Forgery (CSRF) vulnerability affecting the Back To Top WordPress plugin by arkapravamajumder. The flaw impacts all plugin versions up to and including 2.0. The vulnerability is classified under CWE-352: Cross-Site Request Forgery.
An attacker can trick an authenticated user into submitting a forged request that performs unintended state-changing actions within the plugin. Exploitation requires user interaction, such as clicking a crafted link or visiting a malicious page while authenticated to the WordPress admin session.
Critical Impact
Successful exploitation allows attackers to modify plugin settings on behalf of an authenticated administrator through forged HTTP requests, requiring only user interaction to trigger.
Affected Products
- arkapravamajumder Back To Top WordPress plugin — versions up to and including 2.0
- WordPress installations with the backtotop plugin activated
- All configurations where administrators interact with untrusted web content while authenticated
Discovery Timeline
- 2025-03-11 - CVE-2025-28940 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-28940
Vulnerability Analysis
The Back To Top plugin fails to validate the authenticity of state-changing HTTP requests. WordPress plugins typically defend against CSRF using nonce tokens generated by wp_create_nonce() and verified with check_admin_referer() or wp_verify_nonce(). The affected plugin omits or improperly implements this verification on privileged endpoints.
An attacker crafts a malicious webpage or email containing a hidden form or JavaScript payload. When an authenticated WordPress administrator loads the attacker-controlled content, the browser submits the forged request to the vulnerable plugin endpoint. The plugin processes the request using the victim's existing session cookies.
The attack targets confidentiality at a limited scope and impacts integrity by modifying plugin configuration. Availability is not directly affected. The scope remains unchanged, meaning the impact is contained within the vulnerable component.
Root Cause
The root cause is missing or insufficient CSRF token validation on administrative actions exposed by the plugin. WordPress provides built-in nonce APIs to bind requests to a specific user session, but the plugin does not enforce nonce checks before processing sensitive requests.
Attack Vector
The attack vector is network-based and requires user interaction. An authenticated administrator must visit an attacker-controlled page or click a malicious link while their WordPress session is active. The browser automatically attaches session cookies, allowing the forged request to execute with administrative privileges. No prior authentication or elevated permissions are needed by the attacker.
The vulnerability mechanism relies entirely on abuse of the victim's authenticated session context. See the Patchstack CSRF Vulnerability Notice for technical details.
Detection Methods for CVE-2025-28940
Indicators of Compromise
- Unexpected changes to Back To Top plugin configuration in the WordPress admin panel
- Administrative POST requests to plugin endpoints lacking a valid _wpnonce parameter
- HTTP Referer headers on plugin admin actions pointing to external or unrelated domains
- Unusual outbound clicks from administrator email accounts followed by plugin setting changes
Detection Strategies
- Monitor WordPress access logs for requests to plugin administrative endpoints missing the _wpnonce query parameter
- Correlate administrator authentication events with subsequent plugin configuration writes originating from external referrers
- Deploy a Web Application Firewall (WAF) rule that inspects POST requests to /wp-admin/ paths for missing nonce tokens
Monitoring Recommendations
- Enable WordPress audit logging plugins to record configuration changes with source IP and referrer data
- Alert on plugin option modifications occurring outside routine maintenance windows
- Track administrator browser sessions for concurrent visits to untrusted domains during active admin sessions
How to Mitigate CVE-2025-28940
Immediate Actions Required
- Deactivate the Back To Top plugin until a patched release is verified and installed
- Restrict WordPress administrator accounts from browsing untrusted content during active admin sessions
- Enforce administrator use of separate browsers or browser profiles for WordPress management
- Rotate administrator credentials and invalidate active sessions if unauthorized configuration changes are found
Patch Information
At the time of publication, the Patchstack advisory lists affected versions from n/a through 2.0 with no vendor-supplied fix identified. Monitor the plugin repository for a security release addressing the missing nonce validation. Replace the plugin with a maintained alternative if a patched version is not released.
Workarounds
- Remove or disable the backtotop plugin and implement equivalent functionality via a lightweight theme snippet
- Deploy a WAF rule to block requests to plugin admin endpoints that lack a valid WordPress nonce
- Enforce SameSite=Strict cookies on the WordPress session cookie to reduce cross-origin request risk
- Require re-authentication for administrative actions using plugins that add step-up authentication
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
