// For flags

CVE-2023-25194

Apache Kafka Connect API: Possible RCE/Denial of service attack via SASL JAAS JndiLoginModule configuration using Kafka Connect

Severity Score

8.8
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

2
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

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.

A flaw was found in Apache Kafka Connect's REST API that permits configuration of SASL property by an authenticated operator, which could allow connection to a malicious LDAP server and subsequent deserialization of malicious content. This issue could allow an authenticated attacker to cause a denial of service or execute arbitrary code on the server, given presence of vulnerable classes on the server's classpath.

*Credits: Apache Kafka would like to thank to Jari Jääskelä (https://hackerone.com/reports/1529790) and 4ra1n and Y4tacker (they found vulnerabilities in other Apache projects. After discussion between PMC of the two projects, it was finally confirmed that it was the vulnerability of Kafka then they reported it to us)
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2023-02-05 CVE Reserved
  • 2023-02-07 CVE Published
  • 2023-02-09 First Exploit
  • 2024-08-02 CVE Updated
  • 2024-11-11 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
CWE
  • CWE-502: Deserialization of Untrusted Data
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Apache
Search vendor "Apache"
 Kafka Connect
Search vendor "Apache" for product "Kafka Connect"
 >= 2.3.0 <= 3.3.2
Search vendor "Apache" for product "Kafka Connect" and version " >= 2.3.0 <= 3.3.2"
-
Affected