CVE-2024-56128

Technical Description

Incorrect Implementation of Authentication Algorithm in Apache Kafka's SCRAM implementation.

Issue Summary:

Apache Kafka's implementation of the Salted Challenge Response Authentication Mechanism (SCRAM) did not fully adhere to the requirements of RFC 5802 [1].

Specifically, as per RFC 5802, the server must verify that the nonce sent by the client in the second message matches the nonce sent by the server in its first message.

However, Kafka's SCRAM implementation did not perform this validation.

Impact:

This vulnerability is exploitable only when an attacker has plaintext access to the SCRAM authentication exchange. However, the usage of SCRAM over plaintext is strongly

discouraged as it is considered an insecure practice [2]. Apache Kafka recommends deploying SCRAM exclusively with TLS encryption to protect SCRAM exchanges from interception [3].

Deployments using SCRAM with TLS are not affected by this issue.

How to Detect If You Are Impacted:

If your deployment uses SCRAM authent

Remediation

Check the references section for vendor advisories and patches from apache. Update kafka to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

Affected Products

References