CVE-2025-1475 Overview
The WPCOM Member plugin for WordPress contains a critical authentication bypass vulnerability affecting all versions up to and including 1.7.5. The vulnerability stems from insufficient verification on the user_phone parameter when logging in via SMS authentication. This flaw allows unauthenticated attackers to bypass authentication mechanisms and log in as any existing user on the site, including administrators, when SMS login functionality is enabled.
Critical Impact
Unauthenticated attackers can gain complete administrative access to WordPress sites running vulnerable versions of WPCOM Member with SMS login enabled, potentially leading to full site compromise.
Affected Products
- WPCOM Member plugin for WordPress versions up to and including 1.7.5
- WordPress sites with SMS login functionality enabled
- All WordPress installations using the vulnerable plugin versions
Discovery Timeline
- 2025-03-07 - CVE-2025-1475 published to NVD
- 2025-03-07 - Last updated in NVD database
Technical Details for CVE-2025-1475
Vulnerability Analysis
This authentication bypass vulnerability (CWE-287) exists within the WPCOM Member plugin's SMS-based login functionality. The plugin fails to properly validate the user_phone parameter during the authentication process, creating a critical security gap that allows attackers to impersonate any registered user.
The vulnerability is particularly severe because it requires no authentication to exploit and can be triggered remotely over the network. An attacker only needs to know or guess a valid phone number associated with a user account to gain unauthorized access. The lack of proper verification means the authentication system trusts user-supplied input without adequate validation, completely undermining the security of the login mechanism.
Root Cause
The root cause of this vulnerability lies in the insufficient verification logic within the form-validation.php file. The plugin's SMS login implementation fails to properly validate that the user requesting authentication actually controls the phone number being used. This missing verification step allows attackers to manipulate the user_phone parameter and authenticate as arbitrary users without possessing the actual phone or receiving the SMS verification code.
Attack Vector
The attack can be executed remotely over the network without requiring any prior authentication or user interaction. An attacker targeting a WordPress site with the vulnerable plugin installed would:
- Identify that the target site uses WPCOM Member with SMS login enabled
- Obtain or enumerate valid phone numbers associated with user accounts (particularly administrators)
- Craft a malicious login request with a manipulated user_phone parameter
- Bypass the authentication mechanism entirely
- Gain full access to the targeted user account
The vulnerability is documented in the WordPress Form Validation File where the insufficient validation occurs. Technical details can also be found in the Wordfence Vulnerability Report.
Detection Methods for CVE-2025-1475
Indicators of Compromise
- Unusual login activity for administrator or privileged accounts without corresponding SMS verification logs
- Multiple authentication attempts using different phone numbers for the same account
- Login events from unexpected IP addresses or geographic locations for known user accounts
- Audit log entries showing successful authentication without proper verification flow completion
Detection Strategies
- Monitor WordPress authentication logs for anomalous login patterns, particularly focusing on SMS-based authentication events
- Implement Web Application Firewall (WAF) rules to detect and block suspicious requests targeting the WPCOM Member login endpoints
- Review server access logs for repeated requests to form validation endpoints with varying user_phone parameters
- Deploy endpoint detection solutions to identify post-exploitation activities following unauthorized access
Monitoring Recommendations
- Enable comprehensive logging for all authentication events in WordPress
- Configure alerts for administrator account logins from new devices or IP addresses
- Implement rate limiting on SMS login functionality to detect enumeration attempts
- Regularly audit user sessions and active logins for unexpected access patterns
How to Mitigate CVE-2025-1475
Immediate Actions Required
- Update the WPCOM Member plugin to the latest patched version immediately
- Disable SMS login functionality until the patch can be applied
- Review WordPress user accounts for any unauthorized access or privilege changes
- Reset passwords and invalidate existing sessions for all administrator accounts
- Audit the site for any indicators of compromise or unauthorized modifications
Patch Information
A security patch addressing this vulnerability is available through the WordPress Changeset Update. Site administrators should update the WPCOM Member plugin to the latest version that includes the fix for this authentication bypass vulnerability. The patch implements proper verification of the user_phone parameter to ensure that only legitimate users can authenticate via SMS login.
Workarounds
- Disable the SMS login feature in WPCOM Member plugin settings until the patch is applied
- Implement additional authentication factors that do not rely solely on the vulnerable SMS verification
- Restrict administrative access to trusted IP addresses using .htaccess or firewall rules
- Consider temporarily deactivating the WPCOM Member plugin if SMS login cannot be disabled independently
# Disable WPCOM Member plugin via WP-CLI until patched
wp plugin deactivate wpcom-member
# Or restrict access to wp-login.php and admin areas via .htaccess
# Add to .htaccess in WordPress root directory
<Files wp-login.php>
Order Deny,Allow
Deny from all
Allow from 192.168.1.0/24
</Files>
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
