MongoDB Server TLS Handshake Validation Vulnerability

A vulnerability exists in MongoDB Server in versions 7.0 prior to 7.0.26, 8.0 prior to 8.0.16, and 8.2 prior to 8.2.2, allowing clients to successfully complete a TLS handshake with the server even when the client certificate does not meet the specified Extended Key Usage (EKU) requirements. This issue arises on MongoDB servers running Windows or Apple, where the validation process fails to enforce the correct EKU specifications for client and server certificates. As a result, certificates can be improperly authenticated, leading to potential security risks.

Impact

Exploitation of this vulnerability allows for improper authentication of TLS certificates, which could lead to non-compliance with established security protocols and potentially facilitate unauthorized access or actions within the MongoDB server.

Reproduction

The vulnerability can be reproduced by creating a client certificate that includes the 'extendedKeyUsage' field but omits 'clientAuth', and then using this certificate to authenticate with a MongoDB server via a TLS connection. The server will accept the connection, despite the certificate not meeting the EKU requirements for client authentication. Similarly, the issue can be reproduced with server certificates by presenting one that lacks the 'serverAuth' EKU while still being accepted by the MongoDB server.

Remediation

Users can upgrade to MongoDB Server versions 7.0.26, 8.0.16, or 8.2.2, where this vulnerability has been addressed.