A recently identified security vulnerability in Apache Tomcat’s Common Gateway Interface (CGI) servlet could enable attackers to bypass established security constraints under specific conditions. This flaw, designated as CVE-2025-46701, was disclosed on May 29, 2025, and affects multiple versions of the widely-used Java application server.
Understanding the Vulnerability
The core issue arises from improper handling of case sensitivity within Apache Tomcat’s CGI servlet, particularly concerning the `pathInfo` component of URLs mapped to the CGI servlet. When Tomcat operates on case-insensitive file systems with security constraints configured for the `pathInfo` component, specially crafted URLs can circumvent these protective measures. This vulnerability is classified as low severity but poses a significant risk for organizations relying on CGI-based applications with strict access controls.
Affected Versions
The vulnerability impacts a broad range of Apache Tomcat versions across three major release branches:
– 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
This extensive range means that numerous production environments could potentially be vulnerable, especially those that have enabled CGI support for legacy applications or specific development workflows.
Mitigation and Patching
The Apache Software Foundation has released patched versions addressing this vulnerability across all affected branches. Organizations are advised to upgrade to the following versions:
– Apache Tomcat 11.0.7
– Apache Tomcat 10.1.41
– Apache Tomcat 9.0.105
These updates include proper case sensitivity handling within the CGI servlet implementation, effectively mitigating the vulnerability.
Recommendations for System Administrators
System administrators should take the following steps to secure their Apache Tomcat deployments:
1. Assess CGI Support: Determine if CGI support is enabled in your Tomcat installations. Since CGI support is disabled by default, enabling it requires explicit configuration.
2. Review Security Constraints: Examine security constraints applied to the `pathInfo` component, especially if operating on case-insensitive file systems.
3. Apply Patches Promptly: Upgrade to the patched versions mentioned above to address the vulnerability.
4. Disable Unnecessary Features: If CGI functionality is not required, ensure it remains disabled to reduce the attack surface.
5. Conduct Regular Security Audits: Regularly review and update security configurations to maintain a robust security posture.
Conclusion
The discovery of CVE-2025-46701 highlights the importance of continuous security assessment and prompt patching in widely-deployed software components. Organizations utilizing Apache Tomcat should prioritize evaluating their configurations and applying necessary updates to safeguard against potential exploits.
