CVE-2025-47523: Seznam Webmaster CSRF Vulnerability

CVE-2025-47523 Overview

CVE-2025-47523 is a Cross-Site Request Forgery (CSRF) vulnerability in the Seznam Webmaster WordPress plugin developed by Lukáš Hartmann. The flaw affects all versions up to and including 1.4.7. The vulnerability is classified under CWE-352 and allows attackers to trick authenticated users into performing unintended state-changing actions on the plugin. Exploitation requires user interaction, typically by luring a logged-in administrator to a malicious page.

Critical Impact

Successful exploitation allows attackers to perform unauthorized actions within the Seznam Webmaster plugin context by leveraging an authenticated user's session, resulting in limited integrity impact on affected WordPress sites.

Affected Products

• Lukáš Hartmann Seznam Webmaster plugin for WordPress
• Seznam Webmaster versions from n/a through 1.4.7
• WordPress installations with the seznam-webmaster plugin enabled

Discovery Timeline

• 2025-05-07 - CVE-2025-47523 published to the National Vulnerability Database
• 2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-47523

Vulnerability Analysis

The Seznam Webmaster plugin fails to validate the origin of state-changing HTTP requests. Sensitive plugin actions do not verify a WordPress nonce or equivalent anti-CSRF token before execution. An attacker crafts a malicious HTML page containing a form or script that submits a request to the vulnerable endpoint. When an authenticated administrator visits the page, the browser automatically attaches session cookies and executes the forged request.

The issue impacts integrity but does not directly expose confidential data or degrade availability. Exploitation is limited to actions the victim user is authorized to perform. Because the attack occurs over the network and requires only a single click or page visit, the risk to unpatched WordPress sites remains material.

EPSS data indicates a low observed exploitation probability at the time of publication, and no public exploit is currently listed in Exploit-DB or the CISA Known Exploited Vulnerabilities catalog.

Root Cause

The root cause is missing CSRF protection on privileged plugin actions. The plugin does not call wp_verify_nonce() or check_admin_referer() on the affected request handlers. Without token validation, the server cannot distinguish a legitimate administrator action from a forged cross-origin request.

Attack Vector

The attack vector is network-based and requires user interaction. An attacker hosts or injects a crafted page containing an auto-submitting form or fetch request targeting the vulnerable plugin endpoint. A logged-in WordPress administrator must visit the attacker-controlled content while their session is active. No prior authentication or privileges are required from the attacker.

Refer to the Patchstack WordPress Vulnerability Report for further technical detail.

Detection Methods for CVE-2025-47523

Indicators of Compromise

• Unexpected changes to Seznam Webmaster plugin settings or verification tokens without a corresponding administrator audit log entry
• WordPress access logs showing POST requests to plugin endpoints with Referer headers pointing to external or unfamiliar domains
• Administrator sessions initiating plugin configuration changes shortly after visiting third-party links

Detection Strategies

• Review web server access logs for requests to wp-admin plugin pages containing off-site or missing Referer headers
• Enable WordPress audit logging plugins to capture setting changes and correlate against administrator activity windows
• Monitor for POST requests to plugin endpoints that lack the expected _wpnonce parameter

Monitoring Recommendations

• Alert on modifications to Seznam Webmaster configuration outside of scheduled maintenance windows
• Track browser-side navigation patterns of privileged users to detect visits to untrusted domains before configuration changes
• Correlate WordPress database changes with HTTP request logs to identify forged administrative actions

How to Mitigate CVE-2025-47523

Immediate Actions Required

• Disable the Seznam Webmaster plugin until a patched release above 1.4.7 is confirmed available and installed
• Instruct WordPress administrators to log out of admin sessions when not actively managing the site
• Restrict access to /wp-admin/ by source IP address where operationally feasible

Patch Information

At the time of publication, the vendor advisory tracked through Patchstack identifies all versions through 1.4.7 as affected. Administrators should monitor the WordPress plugin repository for an updated release from the maintainer and apply it immediately once published.

Workarounds

• Deploy a Web Application Firewall rule that enforces same-origin Referer and Origin header validation on wp-admin POST requests
• Use a security plugin that adds nonce enforcement or CSRF protection at the WordPress application layer
• Segment administrator browsing by using a dedicated browser profile solely for WordPress management

# Example WAF rule concept: block wp-admin POST requests missing a same-origin Referer
# (Adapt syntax for your specific WAF platform)
SecRule REQUEST_METHOD "@streq POST" \
  "chain,deny,status:403,id:1004752301,\
  msg:'CSRF protection - wp-admin request missing valid Referer'"
  SecRule REQUEST_URI "@beginsWith /wp-admin/" "chain"
    SecRule &REQUEST_HEADERS:Referer "@eq 0"