CVE-2025-28941 Overview
CVE-2025-28941 is a Cross-Site Request Forgery (CSRF) vulnerability in the ohtan Spam Byebye (spam-byebye) WordPress plugin. The flaw affects all plugin versions from n/a through 2.2.4. Attackers can trick authenticated WordPress administrators into submitting forged requests that alter plugin state without their consent. The weakness is classified under CWE-352: Cross-Site Request Forgery.
Critical Impact
Successful exploitation requires user interaction from an authenticated administrator but enables unauthorized state-changing actions against the WordPress plugin.
Affected Products
- ohtan Spam Byebye WordPress plugin (spam-byebye)
- All versions up to and including 2.2.4
- WordPress sites with the plugin installed and active
Discovery Timeline
- 2025-03-11 - CVE-2025-28941 published to the National Vulnerability Database (NVD)
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-28941
Vulnerability Analysis
CVE-2025-28941 stems from missing or improperly implemented anti-CSRF protections in the Spam Byebye WordPress plugin. The plugin exposes state-changing endpoints that do not adequately validate the origin or authenticity of incoming requests. WordPress typically relies on nonce tokens generated by wp_create_nonce() and validated via check_admin_referer() or wp_verify_nonce() to defend against CSRF. When these checks are absent or weak, an attacker-controlled page can trigger privileged actions using the victim's active session.
Because the plugin handles spam filtering configuration, forged requests may alter spam handling rules, disable protective settings, or modify plugin state. The impact is limited to integrity, with no direct confidentiality or availability consequences documented.
Root Cause
The root cause is the absence of adequate CSRF token verification on sensitive request handlers within the spam-byebye plugin. Administrative actions can be invoked through crafted HTML forms or JavaScript hosted on external sites. WordPress session cookies are automatically attached to these cross-origin requests when the administrator visits the malicious page.
Attack Vector
Exploitation requires an authenticated WordPress administrator to visit an attacker-controlled URL or click a crafted link. The attacker embeds a hidden form or auto-submitting script that targets a vulnerable plugin endpoint. Once the request is delivered with the victim's session cookies, the server processes it as a legitimate administrative action. No credentials or elevated privileges are required from the attacker directly, only social engineering to lure the administrator.
See the Patchstack Vulnerability Report for additional technical details.
Detection Methods for CVE-2025-28941
Indicators of Compromise
- Unexpected changes to Spam Byebye plugin settings without corresponding administrative activity in audit logs
- HTTP POST requests to spam-byebye plugin endpoints originating from an external Referer header
- Administrator sessions performing plugin configuration actions immediately after visiting external links or emails
Detection Strategies
- Review web server access logs for requests to wp-admin pages related to spam-byebye with mismatched or missing Referer headers
- Correlate WordPress audit log entries with browser history or email activity around the time of configuration changes
- Deploy a Web Application Firewall (WAF) rule to flag requests to plugin admin endpoints lacking valid nonce parameters
Monitoring Recommendations
- Enable a WordPress activity logging plugin to capture all administrative configuration changes
- Monitor for anomalous outbound traffic from administrator workstations that precedes plugin setting changes
- Alert on any modification to spam filtering rules or plugin options performed outside of change-control windows
How to Mitigate CVE-2025-28941
Immediate Actions Required
- Deactivate the spam-byebye plugin until a patched version is confirmed available from the vendor
- Restrict WordPress administrator browsing to trusted resources and enforce separate browser profiles for admin sessions
- Audit recent plugin configuration changes and revert any unauthorized modifications
Patch Information
As of the latest NVD data, no fixed version beyond 2.2.4 is listed. Monitor the Patchstack Vulnerability Report and the plugin's WordPress.org page for a security update. Apply any released patch immediately once available.
Workarounds
- Uninstall the spam-byebye plugin and use an alternative spam filtering solution with active maintenance
- Enforce two-step verification on administrator accounts and use short session lifetimes to reduce CSRF exposure
- Implement a WAF ruleset that blocks state-changing requests to plugin endpoints without valid WordPress nonce parameters
# Example: disable the vulnerable plugin via WP-CLI
wp plugin deactivate spam-byebye
wp plugin delete spam-byebye
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
