CVE-2025-31921 Overview
CVE-2025-31921 is a Cross-Site Request Forgery (CSRF) vulnerability [CWE-352] affecting the loopus WP Ultimate Tours Builder plugin for WordPress. The flaw impacts all versions of WP_UltimateToursBuilder up to and including 1.055. An attacker can trick an authenticated user into submitting a forged request that performs unintended actions within the plugin. Exploitation requires user interaction, typically by luring a logged-in victim to a malicious page. The Exploit Prediction Scoring System (EPSS) places this issue in the 3.784 percentile, indicating low observed exploitation likelihood.
Critical Impact
Successful exploitation allows an attacker to perform plugin actions in the context of an authenticated WordPress user without their consent, resulting in limited integrity impact on the affected site.
Affected Products
- loopus WP Ultimate Tours Builder (WP_UltimateToursBuilder) plugin for WordPress
- All versions from n/a through 1.055
- WordPress sites running the vulnerable plugin version
Discovery Timeline
- 2025-05-16 - CVE-2025-31921 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-31921
Vulnerability Analysis
The vulnerability is a Cross-Site Request Forgery weakness in the WP Ultimate Tours Builder WordPress plugin. The plugin exposes state-changing actions that do not adequately verify the origin or intent of incoming requests. An attacker can craft a malicious web page or email that, when visited by an authenticated WordPress user, submits a forged request to the vulnerable site. The forged request executes with the victim's session privileges. According to the CVSS vector, the attack requires user interaction and yields limited integrity impact without affecting confidentiality or availability.
Root Cause
The root cause is missing or insufficient CSRF protection on plugin request handlers. WordPress plugins typically enforce CSRF protection through nonce tokens generated by wp_create_nonce() and validated with check_admin_referer() or wp_verify_nonce(). The vulnerable handlers in WP_UltimateToursBuilder fail to validate a nonce or perform equivalent origin verification before processing authenticated actions.
Attack Vector
The attack proceeds over the network and requires user interaction. An attacker hosts a page containing a crafted HTML form or JavaScript that auto-submits a request to the target WordPress site. When an authenticated administrator or privileged user visits the attacker's page, the browser attaches valid session cookies to the outbound request. The vulnerable plugin endpoint processes the request as if the victim had initiated it. Refer to the Patchstack advisory for WP Ultimate Tours Builder for technical details.
No public proof-of-concept exploit or exploit database entry is currently associated with this CVE.
Detection Methods for CVE-2025-31921
Indicators of Compromise
- Unexpected changes to WP Ultimate Tours Builder configuration, tours, or content entries made by administrator accounts
- HTTP POST requests to plugin endpoints with Referer headers pointing to external, untrusted domains
- Administrative actions performed immediately after users click external links or visit unfamiliar sites
Detection Strategies
- Inspect WordPress web server access logs for requests to WP Ultimate Tours Builder endpoints that lack a valid Referer matching the site domain
- Enable WordPress audit logging to correlate plugin state changes with the originating user session and request source
- Monitor for administrative actions occurring without corresponding admin panel navigation activity
Monitoring Recommendations
- Alert on plugin configuration changes performed outside expected administrative workflows or maintenance windows
- Track anomalous POST requests to /wp-admin/admin.php or /wp-admin/admin-post.php targeting plugin actions
- Review WordPress user activity for privileged actions triggered by low-frequency admin sessions
How to Mitigate CVE-2025-31921
Immediate Actions Required
- Identify all WordPress installations running the WP_UltimateToursBuilder plugin at version 1.055 or earlier
- Upgrade the plugin to a patched release once the vendor publishes a fixed version
- Restrict administrator browsing habits and require administrators to log out of WordPress sessions when not actively managing the site
Patch Information
At the time of NVD publication, no fixed version is listed in the advisory. Site operators should monitor the Patchstack advisory and the plugin's official update channel for a release that adds nonce validation to affected handlers.
Workarounds
- Deactivate and remove the WP Ultimate Tours Builder plugin until a patched version is available if it is not business-critical
- Deploy a web application firewall rule that blocks POST requests to plugin endpoints lacking a same-origin Referer header
- Enforce the use of separate browsers or browser profiles for WordPress administrative sessions to reduce CSRF exposure
- Apply the SameSite=Strict cookie attribute on WordPress authentication cookies where compatible with site functionality
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
