CVE-2025-30535 Overview
CVE-2025-30535 is a Cross-Site Request Forgery (CSRF) vulnerability [CWE-352] affecting the External image replace WordPress plugin developed by muro. The flaw impacts all plugin versions up to and including 1.0.8. An attacker can craft a malicious web page or link that, when visited by an authenticated administrator, triggers unauthorized settings changes on the target WordPress site. Exploitation requires user interaction because the victim must be logged in and click or load the attacker-controlled content. The vulnerability does not expose confidential data or affect availability, but it does allow limited integrity impact through unauthorized configuration modification.
Critical Impact
An authenticated administrator visiting an attacker-controlled page can have plugin settings modified without consent, altering how external image replacement behaves on the affected WordPress site.
Affected Products
- muro External image replace WordPress plugin versions n/a through 1.0.8
- WordPress sites with the external-image-replace plugin installed and active
- Administrator accounts authenticated to affected WordPress instances
Discovery Timeline
- 2025-03-24 - CVE-2025-30535 published to the National Vulnerability Database
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-30535
Vulnerability Analysis
The vulnerability stems from missing CSRF protections on state-changing endpoints exposed by the external-image-replace plugin. WordPress provides a nonce mechanism through functions such as wp_nonce_field() and check_admin_referer() to validate that a request originated from a legitimate administrative session. The affected plugin fails to enforce this check on one or more of its settings handlers.
An attacker who knows the structure of the vulnerable request can host a page containing an auto-submitting form or hidden image tag targeting the WordPress admin endpoint. When an authenticated administrator loads the attacker page, the browser attaches session cookies to the outbound request and the plugin processes it as legitimate. The EPSS score is 0.197% at the 9.621 percentile, indicating low observed exploitation activity to date.
Root Cause
The plugin does not validate a WordPress nonce or verify the HTTP Referer header before accepting settings-modification requests. This gap allows any origin to trigger privileged actions on behalf of a logged-in administrator.
Attack Vector
Exploitation is network-based and requires victim interaction. The attacker delivers a link or embedded resource, typically through phishing, malicious advertising, or a compromised third-party site. The victim must hold an active WordPress admin session at the time the request fires. No credentials or elevated privileges are required on the attacker side. See the Patchstack CSRF Vulnerability Notice for the disclosed technical details.
Detection Methods for CVE-2025-30535
Indicators of Compromise
- Unexpected changes to external-image-replace plugin settings appearing in WordPress admin logs
- Inbound POST requests to plugin administrative endpoints containing external Referer headers or no Referer at all
- Administrator session activity immediately following visits to unfamiliar external sites
Detection Strategies
- Monitor WordPress database changes to wp_options entries related to the plugin for unauthorized modification.
- Inspect web server access logs for POST requests to plugin admin URLs where the Referer does not match the site's own domain.
- Correlate administrator browser activity with subsequent plugin configuration changes to identify CSRF-driven events.
Monitoring Recommendations
- Enable a WordPress audit logging plugin to record settings changes with timestamps and originating user context.
- Alert on plugin configuration modifications that occur outside standard administrative workflows or maintenance windows.
- Review reverse proxy or web application firewall logs for suspicious cross-origin form submissions targeting /wp-admin/ paths.
How to Mitigate CVE-2025-30535
Immediate Actions Required
- Identify all WordPress sites running the external-image-replace plugin at version 1.0.8 or earlier.
- Deactivate and remove the plugin until a patched release is verified and installed.
- Require administrators to log out of WordPress when not actively performing site management tasks.
- Force password rotation and session invalidation for any administrator whose account may have been abused during the exposure window.
Patch Information
At the time of publication, no fixed version beyond 1.0.8 is referenced in the available advisory data. Site owners should consult the Patchstack CSRF Vulnerability Notice and the WordPress plugin repository for updated releases from the vendor.
Workarounds
- Deploy a web application firewall rule that blocks POST requests to plugin admin endpoints lacking a same-origin Referer header.
- Restrict WordPress administrative access to trusted IP ranges through server or reverse proxy configuration.
- Use browser isolation or dedicated administrative browsers to reduce the risk of a CSRF payload firing during normal browsing.
- Instruct administrators to avoid clicking untrusted links while logged into the WordPress dashboard.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
