CVE-2025-46701: Apache Tomcat Auth Bypass Vulnerability

CVE-2025-46701 Overview

Improper Handling of Case Sensitivity vulnerability in Apache Tomcat's GCI servlet allows security constraint bypass of security constraints that apply to the pathInfo component of a URI mapped to the CGI servlet.

Critical Impact

This vulnerability can allow attackers to bypass security constraints, leading to unauthorized access and potential data exfiltration.

Affected Products

• Apache Tomcat 11.0.0-M1 through 11.0.6
• Apache Tomcat 10.1.0-M1 through 10.1.40
• Apache Tomcat 9.0.0.M1 through 9.0.104

Discovery Timeline

• Not Available - Vulnerability discovered by Not Available
• Not Available - Responsible disclosure to Apache
• Not Available - CVE CVE-2025-46701 assigned
• Not Available - Apache releases security patch
• 2025-05-29 - CVE CVE-2025-46701 published to NVD
• 2025-11-03 - Last updated in NVD database

Technical Details for CVE-2025-46701

Vulnerability Analysis

This vulnerability stems from Apache Tomcat’s improper handling of case sensitivity in the GCI servlet, allowing attackers to bypass defined security constraints by manipulating the pathInfo component of URIs.

Root Cause

The root cause is a logic error in case sensitivity checks within the URI handling mechanism of the CGI servlet.

Attack Vector

The vulnerability can be exploited over the Network by crafting specific URIs that bypass security constraints.

// Example exploitation code (sanitized)
String url = "/example/PathInfo";
// The following URI could bypass constraints:
String craftedUrl = url.toLowerCase();

Detection Methods for CVE-2025-46701

Indicators of Compromise

• Unusual HTTP requests with mixed or unexpected case in URIs
• Access logs showing unauthorized access to secured paths
• Repeated failed authentication attempts followed by successful access

Detection Strategies

Implement monitoring for unexpected case variations in pathInfo elements of URIs using intrusion detection systems.

Monitoring Recommendations

Configure your logging infrastructure to alert on variations in case sensitivity within URI paths, particularly concerning the CGI servlet.

How to Mitigate CVE-2025-46701

Immediate Actions Required

• Update to Apache Tomcat version 11.0.7, 10.1.41, or 9.0.105
• Harden CGI servlet configurations
• Review and tighten access control mechanisms

Patch Information

Security patches are available in Apache Tomcat versions 11.0.7, 10.1.41, and 9.0.105. It is imperative to update to these versions to mitigate the vulnerability.

Workarounds

While upgrading is recommended, a potential workaround is to enforce strict case sensitivity in URI parsing through application layer validation.

# Configuration example: Enforce case sensitivity
<Location "/example/">
    AllowOverride None
    Options None
    Require all granted
    # Custom directive to enforce URI case sensitivity
    RewriteEngine On
    RewriteMap lc int:tolower
    RewriteCond %{REQUEST_URI} ^/example/([A-Z].*)$ [NC]
    RewriteRule . - [F,L]
</Location>