Apache Software Foundation · Apache Kafka Connect API
Apache Kafka Connect API contains a flaw in how it handles SASL JAAS configuration for connector Kafka clients, allowing the com.sun.security.auth.module.JndiLoginModule to be set through the producer, consumer, or admin override properties. An authenticated operator with access to a Kafka Connect worker's REST API, able to create or modify connectors, can exploit this to make the server contact an attacker-controlled LDAP server and deserialize its response, enabling unrestricted deserialization and remote code execution where suitable gadgets exist on the classpath.
A possible security vulnerability has been identified in Apache Kafka Connect API. This requires access to a Kafka Connect worker, and the ability to create/modify connectors on it with an arbitrary Kafka client SASL JAAS config and a SASL-based security protocol, which has been possible on Kafka Connect clusters since Apache Kafka Connect 2.3.0. When configuring the connector via the Kafka Connect REST API, an authenticated operator can set the `sasl.jaas.config` property for any of the connector's Kafka clients to "com.sun.security.auth.module.JndiLoginModule", which can be done via the `producer.override.sasl.jaas.config`, `consumer.override.sasl.jaas.config`, or `admin.override.sasl.jaas.config` properties. This will allow the server to connect to the attacker's LDAP server and deserialize the LDAP response, which the attacker can use to execute java deserialization gadget chains on the Kafka connect server. Attacker can cause unrestricted deserialization of untrusted data (or) RCE vulnerability when there are gadgets in the classpath. Since Apache Kafka 3.0.0, users are allowed to specify these properties in connector configurations for Kafka Connect clusters running with out-of-the-box configurations. Before Apache Kafka 3.0.0, users may not specify these properties unless the Kafka Connect cluster has been reconfigured with a connector client override policy that permits them. Since Apache Kafka 3.4.0, we have added a system property ("-Dorg.apache.kafka.disallowed.login.modules") to disable the problematic login modules usage in SASL JAAS configuration. Also by default "com.sun.security.auth.module.JndiLoginModule" is disabled in Apache Kafka Connect 3.4.0. We advise the Kafka Connect users to validate connector configurations and only allow trusted JNDI configurations. Also examine connector dependencies for vulnerable versions and either upgrade their connectors, upgrading that specific dependency, or removing the connectors as options for remediation. Finally, in addition to leveraging the "org.apache.kafka.disallowed.login.modules" system property, Kafka Connect users can also implement their own connector client config override policy, which can be used to control which Kafka client properties can be overridden directly in a connector config and which cannot.
First seen exploited 15 months after disclosure. Public exploit code (Metasploit) was available the same day.
2 related vulnerabilities in the same code over 2 years.
Why these are linked: Link confidenceHow strong the evidence is that two CVEs are related. High: stated in the CVE text or linked in an advisory, or the same code was patched one release apart. Medium: the same code, or a version step plus a similar description. Low: similar description only.
No ATT&CK techniques are linked to this CVE yet. MITRE CTID has not mapped it, and no report passage in the corpus ties it to a technique.
1 package in 1 ecosystem. Main package: org.apache.kafka:connect.
Upgrade to 3.4.0 or later
Set the version to 3.4.0 or later in your pom.xml or build.gradle.
The first fix for CVE-2023-25194. No other CVE tracked by Patchfirst affects this package.
| If you run | Upgrade to |
|---|---|
| 2.3.0 up to 3.4.0 | 3.4.0 |
“Up to” means the second version is the fix and is not affected.