CVE-2024-56128 — KAFKA
MEDIUMCVE-2024-56128 is a medium-severity (CVSS 5.3) CWE-303 vulnerability in apache kafka. A fix is available — see the affected versions and patch details below.
Incorrect Implementation of Authentication Algorithm in Apache Kafka's SCRAM implementation. Issue Summary: Apache Kafka's implementation of the Salted Challenge Response Authentication…
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2024-56128.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2024-56128 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,636 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
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 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.
Affected Products
kafkaapacheDetection & mitigation playbook
Vendor / applianceDetect
Inventory every apache kafka deployment and check each version against the affected-products list above. Because the exploit targets the running system rather than your application code, also watch for exploitation at the network and runtime layer — O3 flags the exploit behaviour from runtime telemetry and egress traffic even before a vulnerable build is confirmed.
Fix
Apply the apache kafka security patch or hotfix for CVE-2024-56128 on the affected version, following the vendor advisory for your exact build.
Workarounds
Cut exposure now: restrict the management/admin interface to trusted networks, segment the device, and apply the vendor's recommended configuration mitigations and any WAF/IPS signature. O3's runtime protection blocks the exploit chain at execution, holding the line on unpatched or end-of-life systems until you can patch.
How O3 protects you
O3 detects and blocks CVE-2024-56128 exploitation at runtime: eBPF exploit-chain detection, plus L7 egress monitoring that catches the post-exploitation callback and severs the attacker's outbound channel.
Tailored to CVE-2024-56128. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
This vulnerability is marked with an Important severity because it compromises a fundamental security requirement of the SCRAM protocol as specified in RFC 5802 —the validation of nonces for ensuring message integrity and preventing replay attacks. Without proper nonce validation, an attacker with plaintext access to…
| Product | Fixed in | Advisory |
|---|---|---|
| Streams for Apache Kafka 2.9.1 | see advisory | RHSA-2025:9922 |
| Streams for Apache Kafka 3.0.0 | see advisory | RHSA-2025:12511 |
| Streams for Apache Kafka 3.1.0 | kafka_2.13 | RHSA-2025:23417 |
Frequently Asked Questions
Is CVE-2024-56128 being exploited in your environment?
O3's eBPF runtime sensors and L7 egress monitoring detect and block the CVE-2024-56128 exploit chain at execution — protecting unpatched and end-of-life systems until the vendor patch is applied.