CVE-2025-53347 Overview
CVE-2025-53347 is a Cross-Site Request Forgery (CSRF) vulnerability in the Laborator Kalium WordPress theme. The flaw affects all versions of Kalium up to and including 3.18.3. An attacker can craft a malicious web page that, when visited by an authenticated site user, triggers unintended state-changing actions on the target WordPress site. The vulnerability is tracked under CWE-352: Cross-Site Request Forgery. Exploitation requires user interaction such as clicking a link or loading attacker-controlled content while a valid Kalium session is active.
Critical Impact
An attacker can coerce authenticated users into performing unintended actions on Kalium-powered WordPress sites, resulting in limited integrity impact without requiring credentials.
Affected Products
- Laborator Kalium WordPress theme versions up to and including 3.18.3
- WordPress sites deploying the Kalium theme without a patched release
- Any Kalium installation lacking CSRF token validation on state-changing endpoints
Discovery Timeline
- 2025-08-14 - CVE-2025-53347 published to the National Vulnerability Database
- 2026-06-17 - Last updated in the NVD database
Technical Details for CVE-2025-53347
Vulnerability Analysis
The vulnerability stems from missing or inadequate CSRF protections in the Kalium WordPress theme. State-changing HTTP requests handled by the theme do not require unpredictable, per-request tokens tied to the authenticated user session. An attacker who lures a logged-in user to a malicious page can cause the browser to submit forged requests to the vulnerable site. Because the browser automatically attaches session cookies, the target application processes the request as legitimate. The attack impacts integrity in a limited scope but does not directly expose confidential data or degrade availability.
Root Cause
The root cause is the absence of anti-CSRF controls, such as WordPress nonces (wp_nonce_field, check_admin_referer, or wp_verify_nonce), on sensitive theme endpoints. Without token validation, the server accepts requests based solely on session cookies, which browsers transmit cross-origin by default. This is classified under CWE-352.
Attack Vector
Exploitation follows the standard CSRF pattern. The attacker hosts a page containing an auto-submitting HTML form or a hidden image tag that issues a request to a vulnerable Kalium endpoint. The victim, already authenticated to the target WordPress site, visits the attacker page through phishing or a malicious link. The victim's browser sends the forged request with valid session cookies, and the server executes the attacker-chosen action under the victim's identity. Refer to the Patchstack Kalium Theme Vulnerability advisory for endpoint-level detail.
Detection Methods for CVE-2025-53347
Indicators of Compromise
- Web server access logs showing state-changing POST or GET requests to Kalium theme endpoints with Referer headers pointing to unrelated external domains
- Unexpected configuration or content changes on the WordPress site correlated with specific user sessions
- Requests to Kalium endpoints lacking a valid _wpnonce parameter in query strings or POST bodies
Detection Strategies
- Inspect WordPress access logs for cross-origin requests targeting theme AJAX or admin-post handlers registered by Kalium
- Correlate outbound phishing indicators with subsequent authenticated activity on the WordPress site
- Alert on HTTP requests to theme endpoints that lack expected nonce parameters or contain suspicious Origin headers
Monitoring Recommendations
- Enable WordPress audit logging to record administrative and theme-level configuration changes
- Forward web server and WordPress logs to a central platform for correlation and long-term retention
- Monitor for anomalous session activity such as configuration changes performed immediately after a user follows an external link
How to Mitigate CVE-2025-53347
Immediate Actions Required
- Identify all WordPress sites running the Kalium theme at version 3.18.3 or earlier
- Restrict administrative access to the WordPress dashboard by IP allowlisting where feasible
- Instruct privileged users to log out of the WordPress admin when not actively working on the site
- Deploy a web application firewall rule to inspect and block cross-origin state-changing requests to theme endpoints
Patch Information
Refer to the Patchstack advisory for the Kalium theme for the fixed version. Update the Kalium theme through the WordPress dashboard or by uploading the vendor-supplied release, and verify the theme version reported in the admin interface after the upgrade.
Workarounds
- Enforce SameSite=Lax or SameSite=Strict cookies on the WordPress session to reduce cross-origin cookie transmission
- Require re-authentication for sensitive administrative actions using a security plugin
- Deploy a WAF signature that blocks requests to Kalium endpoints missing a valid _wpnonce parameter
# Example WAF rule concept: block state-changing requests to Kalium endpoints
# when the Origin or Referer header is not the site's own domain
SecRule REQUEST_METHOD "@streq POST" \
"chain,deny,status:403,id:1000353,msg:'Potential CSRF against Kalium theme'"
SecRule REQUEST_URI "@rx /wp-admin/admin-(ajax|post)\.php" "chain"
SecRule REQUEST_HEADERS:Referer "!@beginsWith https://your-site.example/"
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
