CVE-2025-47275 Overview
CVE-2025-47275 is an authentication bypass vulnerability affecting the Auth0-PHP SDK, the foundational PHP SDK for Auth0 Authentication and Management APIs. Starting in version 8.0.0-BETA1 and prior to version 8.14.0, session cookies of applications using the Auth0-PHP SDK configured with CookieStore have authentication tags that can be brute forced, which may result in unauthorized access to protected resources.
Critical Impact
Successful exploitation allows attackers to bypass authentication mechanisms and gain unauthorized access to user sessions without valid credentials.
Affected Products
- Auth0-PHP SDK versions 8.0.0-BETA1 through 8.13.x
- Auth0/symfony SDK (depends on Auth0-PHP SDK)
- Auth0/laravel-auth0 SDK (depends on Auth0-PHP SDK)
- Auth0/wordpress SDK (depends on Auth0-PHP SDK)
Discovery Timeline
- May 15, 2025 - CVE-2025-47275 published to NVD
- May 16, 2025 - Last updated in NVD database
Technical Details for CVE-2025-47275
Vulnerability Analysis
This vulnerability stems from a weakness in the session cookie authentication mechanism within the Auth0-PHP SDK's CookieStore implementation. The authentication tags used to protect session cookies are susceptible to brute force attacks, meaning an attacker with sufficient computational resources can systematically guess valid authentication tags until they find a match.
The vulnerability is classified under CWE-287 (Improper Authentication), indicating that the authentication mechanism does not adequately verify the identity of users or protect session integrity. This allows attackers to forge or manipulate session cookies to impersonate legitimate users.
Root Cause
The root cause lies in the cryptographic implementation of the CookieStore session storage mechanism. The authentication tags protecting session cookies were generated or validated in a manner that made them vulnerable to brute force enumeration. This cryptographic weakness allowed attackers to systematically attempt authentication tag values until achieving a successful match, effectively bypassing the intended security controls.
Certain pre-conditions must be met for exploitation:
- Applications must be using the Auth0-PHP SDK (or dependent SDKs: Auth0/symfony, Auth0/laravel-auth0, Auth0/wordpress)
- Session storage must be configured with CookieStore (not the default session handler)
Attack Vector
The attack is network-based and requires no user interaction or prior authentication. An attacker can intercept or observe encrypted session cookies and then systematically attempt to brute force the authentication tags. Once a valid tag is determined, the attacker can forge session cookies to gain unauthorized access to victim accounts.
The attack mechanism involves:
- Capturing or observing a valid encrypted session cookie from the target application
- Analyzing the cookie structure to identify the authentication tag component
- Systematically generating authentication tag candidates and testing them against the application
- Upon successful brute force, using the forged session cookie to access the victim's authenticated session
For detailed technical analysis of the vulnerability mechanism, refer to the GitHub Security Advisory GHSA-g98g-r7gf-2r25.
Detection Methods for CVE-2025-47275
Indicators of Compromise
- Unusual volume of authentication requests from single IP addresses or IP ranges
- Session cookie validation failures followed by successful authentication without re-authentication
- Anomalous patterns in session token usage across different client fingerprints
- Multiple rapid session creation attempts targeting the same user accounts
Detection Strategies
- Monitor authentication logs for abnormal patterns of failed cookie validation followed by successful access
- Implement rate limiting on authentication endpoints to slow brute force attempts
- Deploy web application firewalls (WAF) with rules to detect cookie manipulation attempts
- Use SentinelOne's behavioral analysis to identify anomalous authentication patterns indicative of session forgery
Monitoring Recommendations
- Enable verbose logging for Auth0-PHP SDK authentication events
- Configure alerting for spikes in authentication failures or session validation errors
- Monitor for multiple sessions created for the same user from geographically disparate locations
- Track cookie decryption failures and authentication tag validation errors in application logs
How to Mitigate CVE-2025-47275
Immediate Actions Required
- Upgrade Auth0-PHP SDK to version 8.14.0 or later immediately
- Rotate all cookie encryption keys as a precautionary measure
- Notify users that previous session cookies will be invalidated upon upgrade
- Review authentication logs for signs of potential exploitation prior to patching
- If using dependent SDKs (Auth0/symfony, Auth0/laravel-auth0, Auth0/wordpress), ensure they are updated to versions that incorporate the fixed Auth0-PHP SDK
Patch Information
Auth0 has released version 8.14.0 of the Auth0-PHP SDK which addresses this vulnerability. The fix can be found in the GitHub commit 52a7948 and is available in the 8.14.0 release.
Related security advisories have been published for dependent SDKs:
- Auth0/laravel-auth0 Security Advisory
- Auth0/symfony Security Advisory
- Auth0/wordpress Security Advisory
Workarounds
- Switch session storage from CookieStore to server-side session storage if immediate upgrade is not possible
- Implement additional session validation checks such as client fingerprinting or IP binding
- Deploy network-level protections to rate-limit authentication requests
- Consider temporarily requiring re-authentication for sensitive operations until the patch is applied
# Update Auth0-PHP SDK via Composer
composer require auth0/auth0-php:^8.14.0
# Rotate cookie encryption keys after upgrade
# This will invalidate all existing sessions
php artisan key:generate # For Laravel applications
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
