CVE-2021-38153
Timing Attack Vulnerability for Apache Kafka Connect and Clients
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- High
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Exploit likelihood
What each source reports
NVD Score used
5.9
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.
- Record
CVE-2021-38153- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N - CVSS 2.0
- 4.3 Medium
AV:N/AC:M/Au:N/C:P/I:N/A:N - Weakness
- CWE-203
- Updated
- 2026-11-02
CVE List No score
Timing Attack Vulnerability for Apache Kafka Connect and Clients
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.
- Record
CVE-2021-38153- Weakness
- CWE-203
- Updated
- 2026-11-02
EUVDEUVD-2021-1963 No score
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.
- Record
EUVD-2021-1963- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-3j6g-hxx5-3q26
5.9
Observable Discrepancy in Apache Kafka
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.
- Record
GHSA-3j6g-hxx5-3q26- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-203
- Updated
- 2026-11-02
OSV
5.9
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.
- Record
CVE-2021-38153- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
OSVGHSA-3j6g-hxx5-3q26
5.9
Observable Discrepancy in Apache Kafka
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.
- Record
GHSA-3j6g-hxx5-3q26- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N - Weakness
- CWE-203
- Updated
- 2026-11-02
OSVUBUNTU-CVE-2021-38153
5.9
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.
- Record
UBUNTU-CVE-2021-38153- CVSS 3.1
- 5.9 Medium
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N - Updated
- 2026-11-02
OSVBIT-kafka-2021-38153 No score
Timing Attack Vulnerability for Apache Kafka Connect and Clients
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.
- Record
BIT-kafka-2021-38153- Updated
- 2026-11-02
Affected products
- apache kafka
- apache software foundation kafka
- oracle communications brm - elastic charging engine
- oracle communications cloud native core policy
- oracle financial services analytical applications infrastructure
- oracle financial services behavior detection platform
- oracle financial services enterprise case management
- oracle primavera unifier
- quarkus
Affected packages
| Package | Affected | Fixed |
|---|---|---|
org.apache.kafka:kafka_2.11Maven |
2.0.0 to 2.4.1 | None known |
org.apache.kafka:kafka_2.12Maven |
2.0.0 up to 2.6.3 | 2.6.3 |
org.apache.kafka:kafka_2.12Maven |
2.7.0 up to 2.7.2 | 2.7.2 |
org.apache.kafka:kafka_2.12Maven |
2.8.0 to 2.8.0 | 2.8.1 |
org.apache.kafka:kafka_2.13Maven |
2.4.0 up to 2.6.3 | 2.6.3 |
org.apache.kafka:kafka_2.13Maven |
2.7.0 up to 2.7.2 | 2.7.2 |
org.apache.kafka:kafka_2.13Maven |
2.8.0 to 2.8.0 | 2.8.1 |
org.apache.kafka:kafka-clientsMaven |
2.0.0 up to 2.6.3 | 2.6.3 |
org.apache.kafka:kafka-clientsMaven |
2.7.0 up to 2.7.2 | 2.7.2 |
org.apache.kafka:kafka-clientsMaven |
2.8.0 to 2.8.0 | 2.8.1 |
Show 12 moreShow less
| Package | Affected | Fixed |
|---|---|---|
kafkaBitnami |
2.0.0 up to 2.6.3, 2.7.0 up to 2.7.2, 2.8.0 up to 2.8.1 | 2.6.32.7.22.8.1 |
org.apache.kafka:kafka_2.11Maven |
2.0.0 to 2.4.1, plus listed versions 2.0.12.1.02.1.12.2.02.2.1 Show 4 moreShow less2.2.22.3.02.3.12.4.0 |
None known |
org.apache.kafka:kafka_2.12Maven |
2.0.0 up to 2.6.3, plus listed versions 2.0.12.1.02.1.12.2.02.2.1 Show 10 moreShow less2.2.22.3.02.3.12.4.02.4.12.5.02.5.12.6.02.6.12.6.2 |
2.6.3 |
org.apache.kafka:kafka_2.12Maven |
2.7.0 up to 2.7.2, plus listed versions 2.7.1 |
2.7.2 |
org.apache.kafka:kafka_2.12Maven |
2.8.0 up to 2.8.1 | 2.8.1 |
org.apache.kafka:kafka_2.13Maven |
2.4.0 up to 2.6.3, plus listed versions 2.4.12.5.02.5.12.6.02.6.12.6.2 |
2.6.3 |
org.apache.kafka:kafka_2.13Maven |
2.7.0 up to 2.7.2, plus listed versions 2.7.1 |
2.7.2 |
org.apache.kafka:kafka_2.13Maven |
2.8.0 up to 2.8.1 | 2.8.1 |
org.apache.kafka:kafka-clientsMaven |
2.0.0 up to 2.6.3, plus listed versions 2.0.12.1.02.1.12.2.02.2.1 Show 10 moreShow less2.2.22.3.02.3.12.4.02.4.12.5.02.5.12.6.02.6.12.6.2 |
2.6.3 |
org.apache.kafka:kafka-clientsMaven |
2.7.0 up to 2.7.2, plus listed versions 2.7.1 |
2.7.2 |
org.apache.kafka:kafka-clientsMaven |
2.8.0 up to 2.8.1 | 2.8.1 |
kafkaUbuntu:Pro:18.04:LTS |
All versions, plus listed versions 2.2.0u2-0ubuntu3.12.2.0u2-0ubuntu3.22.2.2u1-0ubuntu1+esm2 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-38153 is a medium vulnerability (CVSS 5.9) in Apache Kafka, published September 22, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 6.20%, the 93rd percentile. Fixed in org.apache.kafka:kafka_2.12 2.6.3.
References
kafka.apache.org/cve-list
lists.apache.org/thread.html/r35322aec467ddae34002690edaa4d9f16e7df9b5bf7164869b75b62c%40%3Cdev.kafka.apache.org%3E
lists.apache.org/thread.html/r45cc0602d5f2cbb72e48896dfadf5e5b87ed85630449598b40e8f0be%40%3Cdev.kafka.apache.org%3E
lists.apache.org/thread.html/r45cc0602d5f2cbb72e48896dfadf5e5b87ed85630449598b40e8f0be%40%3Cusers.kafka.apache.org%3E
lists.apache.org/thread.html/rd9ef217b09fdefaf32a4e1835b59b96629542db57e1f63edb8b006e6%40%3Cusers.kafka.apache.org%3E
lists.apache.org/thread.html/rd9ef217b09fdefaf32a4e1835b59b96629542db57e1f63edb8b006e6%40%3Cdev.kafka.apache.org%3E
Show 18 moreShow less
lists.apache.org/thread.html/r26390c8b09ecfa356582d665b0c01f4cdcf16ac047c85f9f9f06a88c%40%3Cusers.kafka.apache.org%3E
lists.apache.org/thread.html/r26390c8b09ecfa356582d665b0c01f4cdcf16ac047c85f9f9f06a88c%40%3Cdev.kafka.apache.org%3E
oracle.com/security-alerts/cpujan2022.html
oracle.com/security-alerts/cpuapr2022.html
oracle.com/security-alerts/cpujul2022.html
nvd.nist.gov/vuln/detail/CVE-2021-38153
lists.apache.org/thread.html/r35322aec467ddae34002690edaa4d9f16e7df9b5bf7164869b75b62c@%3Cdev.kafka.apache.org%3E
lists.apache.org/thread.html/r45cc0602d5f2cbb72e48896dfadf5e5b87ed85630449598b40e8f0be@%3Cdev.kafka.apache.org%3E
lists.apache.org/thread.html/r45cc0602d5f2cbb72e48896dfadf5e5b87ed85630449598b40e8f0be@%3Cusers.kafka.apache.org%3E
lists.apache.org/thread.html/rd9ef217b09fdefaf32a4e1835b59b96629542db57e1f63edb8b006e6@%3Cdev.kafka.apache.org%3E
lists.apache.org/thread.html/rd9ef217b09fdefaf32a4e1835b59b96629542db57e1f63edb8b006e6@%3Cusers.kafka.apache.org%3E
lists.apache.org/thread.html/r26390c8b09ecfa356582d665b0c01f4cdcf16ac047c85f9f9f06a88c@%3Cdev.kafka.apache.org%3E
lists.apache.org/thread.html/r26390c8b09ecfa356582d665b0c01f4cdcf16ac047c85f9f9f06a88c@%3Cusers.kafka.apache.org%3E
support.confluent.io/hc/en-us/articles/4407632156692-CVE-2021-38153-Confluent-Platform-Vulnerability-Timing-attacks
github.com/advisories/GHSA-3j6g-hxx5-3q26
github.com/apache/kafka
ubuntu.com/security/CVE-2021-38153
cve.org/CVERecord?id=CVE-2021-38153