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CVE-2021-38153observed exploitationCWE-203

Timing Attack Vulnerability for Apache Kafka Connect and Clients

25Vexday Risk Score

Prioritize patching. It exploitation observed by VulnCheck.

ssvc Attendepss 6.3%
from disclosure to weapon
Published on NVDSep 22
VulnCheck+566d
exploitation probability
6.3%top 7% of all CVEs
observed exploitation
yesVulnCheck
In short

Apache Kafka uses an insecure method to compare passwords and keys, which allows attackers to guess credentials faster by measuring response times. This timing-based weakness makes brute force attacks more practical.

Technical detail

The vulnerability exists in password/key validation logic that uses Arrays.equals, which is not constant-time and leaks information through execution duration variations. An attacker can exploit this timing side-channel to differentiate correct from incorrect credential attempts and accelerate brute force attacks against Kafka Connect and client authentication mechanisms.

Summary generated and translated by AI from the official description.
Some components in Apache Kafka use `Arrays.equals` to validate a password or key, which is vulnerable to timing attacks that make brute force attacks for such credentials more likely to be successful. Users should upgrade to 2.8.1 or higher, or 3.0.0 or higher where this vulnerability has been fixed. The affected versions include Apache Kafka 2.0.0, 2.0.1, 2.1.0, 2.1.1, 2.2.0, 2.2.1, 2.2.2, 2.3.0, 2.3.1, 2.4.0, 2.4.1, 2.5.0, 2.5.1, 2.6.0, 2.6.1, 2.6.2, 2.7.0, 2.7.1, and 2.8.0.