CVE-2025-27819

In CVE-2023-25194, we announced the RCE/Denial of service attack via SASL JAAS JndiLoginModule configuration in Kafka Connect API. But not only Kafka Connect API is vulnerable to this attack, the Apache Kafka brokers also have this vulnerability. To exploit this vulnerability, the attacker needs to be able to connect to the Kafka cluster and have the AlterConfigs permission on the cluster resource.

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 3.4.0, and com.sun.security.auth.module.JndiLoginModule,com.sun.security.auth.module.LdapLoginModule is disabled by default in in Apache Kafka 3.9.1/4.0.0

Weakness

The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.

Affected Software

Potential Mitigations

• Make fields transient to protect them from deserialization.
• An attempt to serialize and then deserialize a class containing transient fields will result in NULLs where the transient data should be. This is an excellent way to prevent time, environment-based, or sensitive variables from being carried over and used improperly.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/586.html

References

• https://kafka.apache.org/cve-list