CVE-2024-7885: Undertow ProxyProtocolReadListener Vulnerability - Potential Data Leakage Across Multiple Requests

A security vulnerability has been identified in the Undertow HTTP server library, specifically affecting the ProxyProtocolReadListener component. The identified issue stems from the reuse of the same StringBuilder instance across multiple requests. This can lead to information leakage between requests or responses and result in errors, connection termination, and unintended data exposure.

Vulnerability Details

The vulnerability stems from the incorrect handling of multiple requests on the same HTTP connection in the parseProxyProtocolV1 method. The ProxyProtocolReadListener reuses the same StringBuilder instance across these requests, which can lead to potential information leakage or unintended data exposure between them.

The primary impact of this issue is the possible disclosure of information between requests or responses. In multi-request environments, this can create a risk for data leakage and lead to security implications.

Affected Versions

This vulnerability affects Undertow versions prior to 2.3..Final.

Code Snippet

Here is a code snippet from the Undertow HTTP server library highlighting the problematic code in the parseProxyProtocolV1 method:

private void parseProxyProtocolV1(final String line) {

        final StringBuilder stringBuilder = new StringBuilder(); // <-- Issue: Reusing the same instance multiple times across different requests

        for (int i = ; i < states.length; ++i) {
            State state = states[i];
            state.parse(buffer, this, stringBuilder);
        }

        // Additional logic to handle request/response procession
}

The above code excerpt demonstrates the problem, where the same StringBuilder instance is being reused multiple times across different requests. Instead of creating a new instance for each request, the instance is shared, potentially leading to information leakage between the requests or their responses.

Exploit

To exploit this vulnerability, an attacker could potentially inject malicious or incorrect data into the StringBuilder instance that's shared between requests. This could cause unintended data exposure from one request to another, leading to information leakage and other security concerns.

Mitigation

The recommended solution is to upgrade Undertow to version 2.3..Final or later, which corrects the issue by ensuring that a new StringBuilder instance is created for each request.

Original References

For more information regarding this vulnerability, please consult the CVE on MITRE's website (CVE-2024-7885) and Undertow's release notes announcing the fix:

- CVE: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-7885
- Undertow release notes: https://github.com/undertow-io/undertow/releases/tag/2.3..Final

Conclusion

CVE-2024-7885 is a data leakage vulnerability in Undertow's ProxyProtocolReadListener, which occurs due to the reuse of a StringBuilder instance across multiple requests. The issue primarily results in errors and connection termination but poses a risk of information leakage and unintended data exposure in multi-request environments. The recommended mitigation is to upgrade Undertow to version 2.3..Final or later, ensuring that unique StringBuilder instances are created for each request.

Timeline

Published on: 08/21/2024 14:15:09 UTC
Last modified on: 08/29/2024 18:18:13 UTC