CVE-2025-1061: Nextend Social Login Pro Auth Bypass Flaw

CVE-2025-1061 Overview

The Nextend Social Login Pro plugin for WordPress contains a critical authentication bypass vulnerability in versions up to and including 3.1.16. This vulnerability stems from insufficient verification of user identity during the Apple OAuth authentication request flow. An unauthenticated attacker who has access to a target user's email address can exploit this flaw to log in as any existing user on the WordPress site, including administrators, effectively gaining complete control over the affected website.

Critical Impact

Unauthenticated attackers can bypass authentication and log in as any existing user, including administrators, by exploiting insufficient verification in Apple OAuth authentication. This can lead to complete site takeover.

Affected Products

• Nextend Social Login Pro plugin for WordPress versions up to and including 3.1.16
• WordPress installations using Apple OAuth authentication through the Nextend Social Login Pro plugin

Discovery Timeline

• February 7, 2025 - CVE-2025-1061 published to NVD
• February 7, 2025 - Last updated in NVD database

Technical Details for CVE-2025-1061

Vulnerability Analysis

This vulnerability is classified as CWE-288: Authentication Bypass Using an Alternate Path or Channel. The core issue lies in how the Nextend Social Login Pro plugin handles Apple OAuth authentication requests. When a user attempts to authenticate via Apple Sign-In, the plugin fails to properly verify that the user being authenticated actually owns the email address being supplied in the OAuth response.

Apple OAuth relies on exchanging identity tokens that contain user information including email addresses. The plugin's implementation does not adequately validate the authenticity and ownership of these tokens before allowing authentication to proceed. This creates a scenario where an attacker who knows a target user's email address can craft or manipulate OAuth requests to impersonate that user.

The impact of this vulnerability is severe because WordPress administrators often have their email addresses exposed through various means—author archives, contact pages, or publicly available business information. Once an attacker gains administrator access, they can install malicious plugins, modify site content, create backdoor accounts, or compromise the underlying server.

Root Cause

The vulnerability exists due to insufficient verification logic in the Apple OAuth authentication handler within the Nextend Social Login Pro plugin. The plugin does not properly validate that the identity token presented during authentication was legitimately issued by Apple for the user attempting to log in. This allows attackers to supply arbitrary email addresses during the authentication flow and gain access to accounts associated with those emails.

Attack Vector

The attack is conducted remotely over the network without requiring any prior authentication or user interaction. An attacker needs only to know the email address of a registered user on the target WordPress site. The attacker initiates the Apple OAuth authentication flow through the vulnerable plugin, manipulates the authentication request to specify the target user's email address, and the plugin's flawed verification allows the attacker to authenticate as that user.

The attack flow involves:

1. Identifying a target WordPress site using Nextend Social Login Pro with Apple OAuth enabled
2. Obtaining the email address of an administrative user (often publicly available)
3. Initiating the Apple OAuth flow and manipulating the authentication request
4. Bypassing verification due to insufficient validation in the plugin
5. Gaining authenticated access as the targeted user

Detection Methods for CVE-2025-1061

Indicators of Compromise

• Unexpected administrator login events, particularly through Apple OAuth authentication
• Login activity from unusual geographic locations or IP addresses for administrative accounts
• New administrator accounts created without authorization
• Modifications to WordPress plugins, themes, or core files without legitimate administrative activity
• Presence of unfamiliar backdoor plugins or PHP files in the WordPress installation

Detection Strategies

• Monitor WordPress authentication logs for Apple OAuth login events, particularly for administrator accounts
• Implement alerting for logins from new or suspicious IP addresses
• Review user account creation logs for unauthorized new accounts with elevated privileges
• Audit installed plugins and themes for unauthorized modifications or additions
• Deploy Web Application Firewall (WAF) rules to detect anomalous OAuth authentication patterns

Monitoring Recommendations

• Enable comprehensive logging for all authentication events in WordPress
• Set up real-time alerting for administrator-level authentication via social login providers
• Monitor for sudden changes in administrator email addresses or account settings
• Implement file integrity monitoring for WordPress core files, plugins, and themes
• Review server access logs for suspicious POST requests to OAuth callback endpoints

How to Mitigate CVE-2025-1061

Immediate Actions Required

• Update Nextend Social Login Pro to version 3.1.17 or later immediately
• Temporarily disable Apple OAuth authentication until the plugin is updated
• Audit all administrator and privileged user accounts for signs of compromise
• Review recent login history for all accounts, especially those with elevated privileges
• Force password resets for all administrator accounts if compromise is suspected

Patch Information

Nextend has released version 3.1.17 of the Social Login Pro plugin which addresses this vulnerability. The fix implements proper verification of Apple OAuth identity tokens to ensure authenticated users legitimately own the email addresses they claim. Site administrators should update through the WordPress admin dashboard or by downloading the latest version from Nextend's official website.

For detailed patch information, refer to the Nextend Pro Addon Changelog and the Wordfence Vulnerability Report.

Workarounds

• Disable Apple OAuth authentication in the Nextend Social Login Pro settings until the plugin can be updated
• Implement additional authentication requirements such as two-factor authentication for all administrator accounts
• Restrict administrator access to known IP addresses using .htaccess or server-level firewall rules
• Consider temporarily disabling social login functionality entirely if unable to update immediately
• Use a Web Application Firewall to add an additional layer of protection against authentication bypass attempts