Important: Authentication Bypass CVE-2023-41081
The modjk component of Apache Tomcat Connectors in some circumstances, such as when a configuration included "JkOptions +ForwardDirectories" but the configuration did not provide explicit mounts for all possible proxied requests, modjk would use an implicit mapping and map the request to the first defined worker. Such an implicit mapping could result in the unintended exposure of the status worker and/or bypass security constraints configured in httpd. As of JK 1.2.49, the implicit mapping functionality has been removed and all mappings must now be via explicit configuration. Only modjk is affected by this issue. The ISAPI redirector is not affected.
This issue affects Apache Tomcat Connectors (modjk only): from 1.2.0 through 1.2.48.
Users are recommended to upgrade to version 1.2.49, which fixes the issue.
History 2023-09-13 Original advisory
2023-09-28 Updated summary
The IIS/ISAPI specific code in the Apache Tomcat JK ISAPI Connector 1.2.0 to 1.2.42 that normalised the requested path before matching it to the URI-worker map did not handle some edge cases correctly. If only a sub-set of the URLs supported by Tomcat were exposed via IIS, then it was possible for a specially constructed request to expose application functionality through the reverse proxy that was not intended for clients accessing Tomcat via the reverse proxy.
A flaw was found in Apache Tomcat JK modjk Connector 1.2.0 to 1.2.44. The Apache Web Server (httpd) specific code that normalised the requested path before matching it to the URI-worker map in Apache Tomcat JK (modjk) Connector did not handle some edge cases correctly. If only a sub-set of the URLs supported by Tomcat were exposed via httpd, then it was possible for a specially constructed request to expose application functionality through the reverse proxy that was not intended for clients accessing the application via the reverse proxy. It was also possible in some configurations for a specially constructed request to bypass the access controls configured in httpd. While there is some overlap between this issue and CVE-2018-1323, they are not identical.
References: https://lists.apache.org/thread.html/6d564bb0ab73d6b3efdd1d6b1c075d1a2c84ecd84a4159d6122529ad@%3Cannounce.tomcat.apache.org%3E