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KafkaApplication · Apache

CVE-2025-27819

HIGH · 7.5 CVSS v3.1 Published 2025-06-10
Fix available
A fix is available. Upgrade to after 3.3.2 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Apache Kafka brokers are vulnerable to RCE/DoS via SASL JAAS JndiLoginModule configuration, allowing attackers with AlterConfigs permission on cluster resources to inject malicious JNDI/LDAP login module configurations. This is an extension of CVE-2023-25194 which previously only addressed Kafka Connect API.

MitigationUpgrade to Apache Kafka 3.4.0 or later (or 3.9.1/4.0.0 for broader protection) OR configure the -Dorg.apache.kafka.disallowed.login.modules system property to disable com.sun.security.auth.module.JndiLoginModule.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
KafkaApplication
Affected:>= 2.0.0, <= 3.3.2

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check installed Kafka version
    Run 'kafka-topics.sh --version' or check the kafka_2.13-<version> directory name, or inspect the 'kafka_duplicate_group_id' or similar metrics jar file, or query the broker via 'kafka-broker-api-versions --bootstrap-server <broker>'
    Affected if The version is greater than or equal to 2.0.0 AND less than or equal to 3.3.2
  2. Verify if SASL authentication is enabled
    Check server.properties for 'security.inter.broker.protocol=SASL_PLAINTEXT' or 'SASL_SSL', or check for 'sasl.mechanism.inter.broker.protocol' settings, or inspect JAAS configuration files referenced by 'java.security.auth.login.config'
    Affected if SASL/SCRAM or SASL/PLAINTEXT authentication is configured and in use
  3. Check if JndiLoginModule is in use in JAAS config
    Inspect all JAAS configuration files (commonly kafka_server_jaas.conf or client_jaas.conf) for occurrences of 'com.sun.security.auth.module.JndiLoginModule' in login module definitions
    Affected if The JndiLoginModule is configured as a login module in any JAAS configuration file used by Kafka brokers or clients
  4. Confirm mitigation property is not set
    Check broker startup scripts (kafka-server-start.sh) and broker JVM options for the system property '-Dorg.apache.kafka.disallowed.login.modules=com.sun.security.auth.module.JndiLoginModule'
    Affected if The disallow property is NOT set AND the Kafka version is in the affected range AND SASL is enabled

A user is affected if they run Kafka 2.0.0 through 3.3.2 with SASL authentication enabled AND the disallowed.login.modules JVM property is not configured to block JndiLoginModule.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to a release after 3.3.2
Interim mitigation

Upgrade to Apache Kafka 3.4.0 or later (or 3.9.1/4.0.0 for broader protection) OR configure the -Dorg.apache.kafka.disallowed.login.modules system property to disable com.sun.security.auth.module.JndiLoginModule.

Recommended fix High confidence

Apache Kafka 3.9.1 or 4.0.0 (or minimum 3.4.0 for basic fix)

  1. Upgrade Apache Kafka to version 3.9.1 or 4.0.0 to ensure full protection against this vulnerability
  2. If upgrading to 3.4.0 - 3.8.x, ensure the system property '-Dorg.apache.kafka.disallowed.login.modules=com.sun.security.auth.module.JndiLoginModule' is set in Kafka startup scripts
  3. Verify after upgrade that SASL JAAS configurations do not use the disabled login modules
  4. Restart Kafka brokers after applying the upgrade
Caveat Ensure any legitimate use of JndiLoginModule in custom JAAS configurations is reviewed and migrated before upgrade; Kafka 3.9.1/4.0.0 also disables LdapLoginModule by default

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Kafka Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,130
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-27819 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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