CVE-2024-56128

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 authentication over plaintext communication channels (without TLS encryption), you are likely impacted.
To check if TLS is enabled, review your server.properties configuration file for listeners property. If you have SASL_PLAINTEXT in the listeners, then you are likely impacted.

Fix Details:
The issue has been addressed by introducing nonce verification in the final message of the SCRAM authentication exchange to ensure compliance with RFC 5802.

Affected Versions:
Apache Kafka versions 0.10.2.0 through 3.9.0, excluding the fixed versions below.

Fixed Versions:
3.9.0
3.8.1
3.7.2

Users are advised to upgrade to 3.7.2 or later to mitigate this issue.

Recommendations for Mitigation:
Users unable to upgrade to the fixed versions can mitigate the issue by:

• Using TLS with SCRAM Authentication:
  Always deploy SCRAM over TLS to encrypt authentication exchanges and protect against interception.
• Considering Alternative Authentication Mechanisms:
  Evaluate alternative authentication mechanisms, such as PLAIN, Kerberos or OAuth with TLS, which provide additional layers of security.

CVE-2024-56128 has a CVSS score of 5.3 (Low). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (3.7.2, 3.8.1); upgrading removes the vulnerable code path.

Kodem intelligence

1. What is CVE-2024-56128? CVE-2024-56128 is a low-severity security vulnerability in org.apache.kafka:kafka_2.13 (maven), affecting versions >= 0.10.2.0, < 3.7.2. It is fixed in 3.7.2, 3.8.1.
2. How severe is CVE-2024-56128? CVE-2024-56128 has a CVSS score of 5.3 (Low). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
3. Which packages are affected by CVE-2024-56128?
   • org.apache.kafka:kafka_2.13 (maven) (versions >= 0.10.2.0, < 3.7.2)
   • org.apache.kafka:kafka_2.12 (maven) (versions >= 0.10.2.0, < 3.7.2)
   • org.apache.kafka:kafka_2.11 (maven) (versions >= 0.10.2.0, <= 2.4.1)
   • org.apache.kafka:kafka_2.10 (maven) (versions >= 0.10.2.0, <= 0.10.2.2)
4. Is there a fix for CVE-2024-56128? Yes. CVE-2024-56128 is fixed in 3.7.2, 3.8.1. Upgrade to this version or later.
5. Is CVE-2024-56128 exploitable, and should I be worried? Whether CVE-2024-56128 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
6. What actually determines whether CVE-2024-56128 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
7. How do I fix CVE-2024-56128?
   • Upgrade org.apache.kafka:kafka_2.13 to 3.7.2 or later
   • Upgrade org.apache.kafka:kafka_2.13 to 3.8.1 or later
   • Upgrade org.apache.kafka:kafka_2.12 to 3.7.2 or later
   • Upgrade org.apache.kafka:kafka_2.12 to 3.8.1 or later