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Fencer Vulns
medium 5.9

CVE-2021-38153 json

Timing Attack Vulnerability for Apache Kafka Connect and Clients

published 2021-09-22 5 y ago modified 2026-09-08 2 mo ago also BIT-kafka-2021-38153 , EUVD-2021-1963 , GHSA-3j6g-hxx5-3q26

cvss
5.9
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
6.2%
EPSS 6.2% chance of exploitation in 30 days, percentile 93%
public exploits
0
none known

Summary

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.

Patch / fix

  • maven org.apache.kafka:kafka_2.12 2.6.3, 2.7.2, 2.8.1
  • maven org.apache.kafka:kafka_2.13 2.6.3, 2.7.2, 2.8.1
  • maven org.apache.kafka:kafka-clients 2.6.3, 2.7.2, 2.8.1
  • bitnami kafka 2.6.3, 2.7.2, 2.8.1
  • apache kafka 2.6.3, 2.7.2
  • quarkus quarkus 2.2.4
  • oracle communications_brm_-_elastic_charging_engine 12.0.0.4.6

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-38153 updated cvss 5.9

Kafka: Timing Attack Vulnerability for Apache Kafka Connect and Clients

  • Red Hat build of Quarkus kafka-clients Red Hat Decision Manager 7 kafka-clients Red Hat Integration Camel Quarkus 1 kafka-clients Red Hat Integration Service Registry kafka-clients
    affected: no fix available
  • Red Hat JBoss Enterprise Application Platform Expansion Pack kafka-clients Red Hat JBoss Fuse 6 kafka-clients
    affected: no fix planned “Out of support scope”
  • Red Hat Process Automation 7 kafka-clients Red Hat streams for Apache Kafka kafka-clients
    affected: no fix available
  • Red Hat AMQ Streams 1.6.6
    fixed: vendor fix RHSA-2022:0219
  • Red Hat AMQ Streams 2.0.0
    fixed: vendor fix RHSA-2022:0138
  • Red Hat build of Quarkus 2.2.5
    fixed: vendor fix RHSA-2022:0589
  • Red Hat Data Grid 8.3.1
    fixed: vendor fix RHSA-2022:2232
  • Red Hat Fuse 7.11
    fixed: vendor fix RHSA-2022:5532
show 5 more
  • Red Hat RHAF Camel-K 1.8
    fixed: vendor fix RHSA-2022:6407
  • Red Hat RHINT Camel-Q 2.7
    fixed: vendor fix RHSA-2022:5606
  • Red Hat RHINT Service Registry 2.0.3 GA
    fixed: vendor fix RHSA-2022:0501
  • Red Hat Vert.x 4.2.5
    fixed: vendor fix RHSA-2022:0737
  • Red Hat Logging Subsystem for Red Hat OpenShift openshift-logging/elasticsearch6-rhel8 Red Hat OpenShift Container Platform 4 openshift4/ose-metering-hive, openshift4/ose-metering-hadoop, openshift4/ose-metering-presto, openshift4/ose-logging-elasticsearch6
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

6.20% chance of exploitation in the next 30 days, higher than 93% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
GitHub 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:P/I:N/A:N
OSV 3.1 5.9 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected packages

ecosystem package affected fixed in
maven org.apache.kafka:kafka_2.11
>=2.0.0, <=2.4.1
 no fix listed
maven org.apache.kafka:kafka_2.12
>=2.0.0, <2.6.3
>=2.7.0, <2.7.2
>=2.8.0, <2.8.1
2.6.3
2.7.2
2.8.1
maven org.apache.kafka:kafka_2.13
>=2.4.0, <2.6.3
>=2.7.0, <2.7.2
>=2.8.0, <2.8.1
2.6.3
2.7.2
2.8.1
maven org.apache.kafka:kafka-clients
>=2.0.0, <2.6.3
>=2.7.0, <2.7.2
>=2.8.0, <2.8.1
2.6.3
2.7.2
2.8.1
bitnami kafka
>=2.0.0, <2.6.3
>=2.7.0, <2.7.2
>=2.8.0, <2.8.1
2.6.3
2.7.2
2.8.1

Affected products

  • Apache Software Foundation Apache Kafka

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.