BIT-tomcat-2025-24813

Path Equivalence: 'file.Name' (Internal Dot) leading to Remote Code Execution and/or Information disclosure and/or malicious content added to uploaded files via write enabled Default Servlet in Apache Tomcat.

This issue affects Apache Tomcat: from 11.0.0 through 11.0.2, from 10.1.0 through 10.1.34, from 9.0.0 through 9.0.98. The following versions were EOL at the time the CVE was created but are known to be affected: 8.5.0 though 8.5.100. Other, older, EOL versions may also be affected.

If all of the following were true, a malicious user was able to view security sensitive files and/or inject content into those files:

• writes enabled for the default servlet (disabled by default)
• support for partial PUT (enabled by default)
• a target URL for security sensitive uploads that was a sub-directory of a target URL for public uploads
• attacker knowledge of the names of security sensitive files being uploaded
• the security sensitive files also being uploaded via partial PUT

If all of the following were true, a malicious user was able to perform remote code execution:

• writes enabled for the default servlet (disabled by default)
• support for partial PUT (enabled by default)
• application was using Tomcat's file based session persistence with the default storage location
• application included a library that may be leveraged in a deserialization attack

Users are recommended to upgrade to version 11.0.3, 10.1.35 or 9.0.99, which fixes the issue.