CVE-2025-57992: Mail Baby SMTP CSRF Vulnerability

CVE-2025-57992 Overview

CVE-2025-57992 is a Cross-Site Request Forgery (CSRF) vulnerability affecting the InterServer Mail Baby SMTP WordPress plugin (mail-baby-smtp). The flaw impacts all versions up to and including 2.8. An attacker can craft a malicious web page that triggers state-changing requests in the plugin when an authenticated administrator visits the page. Successful exploitation requires user interaction but no privileges on the target site. The vulnerability is tracked under CWE-352: Cross-Site Request Forgery.

Critical Impact
Attackers can trick authenticated WordPress administrators into performing unintended actions on the Mail Baby SMTP plugin, potentially altering mail delivery configuration and integrity of outbound email.

Affected Products

InterServer Mail Baby SMTP plugin for WordPress (mail-baby-smtp)
All versions from n/a through 2.8
WordPress sites with the plugin installed and active

Discovery Timeline

2025-09-22 - CVE-2025-57992 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-57992

Vulnerability Analysis

The Mail Baby SMTP plugin fails to validate the origin of state-changing HTTP requests. WordPress plugins are expected to protect sensitive actions with nonces verified through check_admin_referer() or wp_verify_nonce(). When these checks are missing or improperly implemented, a browser session belonging to an authenticated administrator can be abused to submit forged requests.

The attack vector is network-based and requires user interaction. An administrator must visit an attacker-controlled page while authenticated to the WordPress admin console. The plugin then processes the forged request as if it originated from a legitimate admin action. Confidentiality is not directly impacted, but the integrity of plugin configuration — including SMTP server settings, authentication credentials fields, and mail routing options — can be modified.

Because Mail Baby SMTP controls how a WordPress site sends outbound mail, tampering with its configuration can redirect password reset messages, notifications, and transactional email through attacker-controlled infrastructure.

Root Cause

The root cause is missing or insufficient anti-CSRF token validation on plugin administrative endpoints. Requests that modify plugin state do not verify a nonce tied to the current administrator session, allowing cross-origin form submissions to succeed.

Attack Vector

An attacker hosts a malicious page containing an auto-submitting HTML form or JavaScript request targeting a vulnerable plugin endpoint. When a logged-in WordPress administrator visits the page, the browser attaches session cookies and the request executes with administrator privileges. Delivery vectors include phishing emails, malicious ads, or compromised third-party websites.

No verified exploitation code is publicly available. See the Patchstack CSRF Vulnerability Report for the disclosure details.

Detection Methods for CVE-2025-57992

Indicators of Compromise

Unexpected modifications to Mail Baby SMTP plugin settings, including SMTP host, port, username, or from-address fields
WordPress administrator sessions generating POST requests to mail-baby-smtp admin endpoints with Referer headers pointing to external domains
Outbound email routed through unfamiliar SMTP relays after an administrator visited an external link
Access log entries showing plugin configuration URLs invoked without a preceding legitimate admin navigation flow

Detection Strategies

Inspect web server access logs for POST requests to /wp-admin/admin.php?page=mail-baby-smtp or related admin-ajax handlers with mismatched or absent Referer values
Enable WordPress activity logging plugins to record plugin configuration changes and correlate them with the administrator account that triggered them
Compare current plugin settings against a known-good baseline on a regular schedule

Monitoring Recommendations

Alert on any change to Mail Baby SMTP configuration outside of documented maintenance windows
Monitor outbound mail flow for sudden shifts in SMTP relay hostnames or authentication identities
Track administrator browser sessions for cross-origin requests targeting /wp-admin/ endpoints

How to Mitigate CVE-2025-57992

Immediate Actions Required

Update the Mail Baby SMTP plugin to a version later than 2.8 once the vendor publishes a patched release
Audit current plugin configuration and restore any unauthorized changes to SMTP host, credentials, and routing options
Rotate SMTP credentials referenced by the plugin if tampering is suspected
Restrict WordPress administrator accounts to dedicated browser profiles that do not browse untrusted content

Patch Information

At the time of the NVD entry, the advisory identifies affected versions through 2.8 with no confirmed fixed release listed. Administrators should consult the Patchstack CSRF Vulnerability Report and the plugin page on the WordPress.org repository for the latest patched version.

Workarounds

Deactivate the Mail Baby SMTP plugin until a patched version is available if outbound mail configuration can tolerate the change
Deploy a Web Application Firewall (WAF) rule that validates the Referer and Origin headers on requests to plugin admin endpoints
Enforce short WordPress admin session lifetimes and require re-authentication before configuration changes
Require administrators to log out of the WordPress admin console when not actively managing the site

bash

# Example WAF rule concept - block cross-origin POSTs to the plugin admin endpoint
# ModSecurity pseudo-rule
SecRule REQUEST_METHOD "@streq POST" \
  "chain,deny,status:403,id:1057992,msg:'CSRF attempt on mail-baby-smtp'"
SecRule REQUEST_URI "@contains page=mail-baby-smtp" "chain"
SecRule REQUEST_HEADERS:Referer "!@beginsWith https://your-wordpress-site.example/"