CVE-2017-12610 in Kafka
Summary
by MITRE
In Apache Kafka 0.10.0.0 to 0.10.2.1 and 0.11.0.0 to 0.11.0.1, authenticated Kafka clients may use impersonation via a manually crafted protocol message with SASL/PLAIN or SASL/SCRAM authentication when using the built-in PLAIN or SCRAM server implementations in Apache Kafka.
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Analysis
by VulDB Data Team • 03/10/2020
This vulnerability in Apache Kafka represents a critical authentication bypass flaw that allows authenticated clients to impersonate other users through carefully crafted protocol messages. The issue affects versions from 0.10.0.0 through 0.10.2.1 and 0.11.0.0 through 0.11.0.1, where the built-in SASL/PLAIN and SASL/SCRAM server implementations contain a design flaw that permits unauthorized user impersonation. The vulnerability stems from insufficient validation of authentication credentials during the protocol negotiation phase, specifically when clients send crafted messages that manipulate the authentication context.
The technical implementation of this flaw occurs within the SASL authentication mechanisms where the server fails to properly validate the identity claims made by clients during the authentication process. When using PLAIN or SCRAM authentication methods, an authenticated client can construct a malicious protocol message that overrides the expected authentication flow, allowing them to present false credentials and assume the identity of another user within the Kafka cluster. This represents a direct violation of the principle of least privilege and undermines the entire authentication framework. The vulnerability is classified under CWE-287 which deals with improper handling of authentication tokens and credentials, and aligns with ATT&CK technique T1550.001 for use of valid credentials.
The operational impact of this vulnerability is severe as it enables attackers to gain unauthorized access to Kafka topics and resources that should be restricted to specific users or groups. An attacker who has obtained legitimate credentials for a low-privilege account could potentially impersonate high-privilege users, gaining access to sensitive data streams, administrative functions, and potentially causing data breaches or system compromise. The implications extend beyond simple unauthorized access as this flaw could be exploited to perform privilege escalation attacks, modify access controls, or manipulate data flows within the Kafka ecosystem. Organizations using affected Kafka versions face significant risk of data exposure and unauthorized system manipulation.
Mitigation strategies for this vulnerability require immediate patching of affected Kafka versions to the latest releases that contain the authentication fix. Organizations should also implement network segmentation to limit access to Kafka clusters, enforce strict firewall rules, and monitor authentication logs for suspicious activity. Additional security measures include enabling TLS encryption for all Kafka communications, implementing stronger access controls, and regularly auditing user permissions. The fix implemented by Apache Kafka addresses the core issue by strengthening the validation of authentication messages and ensuring that identity claims cannot be overridden through crafted protocol interactions. Security teams should also consider implementing intrusion detection systems specifically designed to monitor for anomalous authentication patterns that might indicate exploitation attempts.