CVE-2023-42795 is an important security vulnerability that affects multiple versions of Apache Tomcat, the widely used open-source Java Servlet container. An error in the recycling process of internal objects in these specific versions can result in a skipped cleanup step, causing sensitive information to leak from the current request/response to the next. This vulnerability has been addressed in recent updates, and users are strongly encouraged to update their Apache Tomcat installations for mitigation.

Exploit Details

The vulnerability occurs when Apache Tomcat recycles various internal objects, an operation that requires proper cleanup steps to remove sensitive information. The affected versions contain an error in this cleanup process, which can lead to an incomplete cleanup. As a result, information from one request/response can potentially leak into another in certain circumstances.

The root cause of this vulnerability is a specific bug in the code that handles the recycling of internal objects. Below is a simplified code snippet of the buggy code:

public void recycle() {
    // Other cleanup code here...
    if (shouldRecycle) {
        // Perform the necessary cleanup
    } else {
        // In some cases, shouldRecycle is false, 
        // and cleanup is not performed as expected.
    }
}

The issue lies in the handling of the shouldRecycle flag. In some cases, the flag remains set to false, causing the necessary cleanup to be skipped.

1. Apache Tomcat Security Advisory: http://tomcat.apache.org/security.html
2. CVE information: https://nvd.nist.gov/vuln/detail/CVE-2023-42795

Mitigation

Users are recommended to upgrade to the following Apache Tomcat versions, which contain the fix for this vulnerability:

Conclusion

CVE-2023-42795 is a significant security vulnerability affecting several versions of Apache Tomcat. Its incomplete cleanup process can potentially cause sensitive information to leak among different request/response processes. By upgrading to the appropriate patched versions, users can effectively address this vulnerability and ensure the security of their applications.

Please visit the links provided for more information on CVE-2023-42795 and the recommended updates.

Timeline

Published on: 10/10/2023 18:15:18 UTC
Last modified on: 11/04/2023 06:15:51 UTC