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.

Published: 2021-09-22 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-38153 is rated Moderate Risk (52.1/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.52%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2021-38153

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-05 1.56% 1.52% -0.04%
2 2026-05-23 1.52% 1.56% +0.04%
3 2026-05-18 — 1.52% —

Full EPSS history (30 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-38153

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.9 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.2 3.6 [email protected]
4.3 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:N/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:N)
No availability impact.
 8.6 2.9 [email protected]

Weakness enumeration for CVE-2021-38153

GitHub Security Advisory for CVE-2021-38153

GHSA-3j6g-hxx5-3q26 · Severity: medium · Ecosystem: maven — Observable Discrepancy in Apache Kafka

OS Trackers for CVE-2021-38153

vendor priority summary link
redhat medium — https://access.redhat.com/security/cve/CVE-2021-38153
ubuntu low CVE-2021-38153 low priority: Ubuntu including 1 source packages (kafka), 15 status rows across 15 suites (bionic, focal, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 12, ignored 1, needed 1, needs-triage 1. https://ubuntu.com/security/CVE-2021-38153

Affected software / configurations for CVE-2021-38153

Vendor Product Version Raw CPE
apache kafka >= 2.0.0, < 2.6.3 cpe:2.3:a:apache:kafka:*:*:*:*:*:*:*:*
apache kafka >= 2.7.0, < 2.7.2 cpe:2.3:a:apache:kafka:*:*:*:*:*:*:*:*
apache kafka 2.8.0 cpe:2.3:a:apache:kafka:2.8.0:-:*:*:*:*:*:*
quarkus quarkus < 2.2.4 cpe:2.3:a:quarkus:quarkus:*:*:*:*:*:*:*:*
oracle communications_brm_-_elastic_charging_engine < 12.0.0.4.6 cpe:2.3:a:oracle:communications_brm_-_elastic_charging_engine:*:*:*:*:*:*:*:*
oracle communications_brm_-_elastic_charging_engine 12.0.0.5.0 cpe:2.3:a:oracle:communications_brm_-_elastic_charging_engine:12.0.0.5.0:*:*:*:*:*:*:*
oracle communications_cloud_native_core_policy 1.15.0 cpe:2.3:a:oracle:communications_cloud_native_core_policy:1.15.0:*:*:*:*:*:*:*
oracle financial_services_analytical_applications_infrastructure >= 8.0.6.0, <= 8.0.9.0 cpe:2.3:a:oracle:financial_services_analytical_applications_infrastructure:*:*:*:*:*:*:*:*
oracle financial_services_analytical_applications_infrastructure >= 8.1.0.0.0, <= 8.1.20 cpe:2.3:a:oracle:financial_services_analytical_applications_infrastructure:*:*:*:*:*:*:*:*
oracle financial_services_behavior_detection_platform >= 8.0.6.0.0, <= 8.0.8.0 cpe:2.3:a:oracle:financial_services_behavior_detection_platform:*:*:*:*:*:*:*:*
oracle financial_services_behavior_detection_platform 8.1.1.0 cpe:2.3:a:oracle:financial_services_behavior_detection_platform:8.1.1.0:*:*:*:*:*:*:*
oracle financial_services_behavior_detection_platform 8.1.1.1 cpe:2.3:a:oracle:financial_services_behavior_detection_platform:8.1.1.1:*:*:*:*:*:*:*
oracle financial_services_behavior_detection_platform 8.1.2.0 cpe:2.3:a:oracle:financial_services_behavior_detection_platform:8.1.2.0:*:*:*:*:*:*:*
oracle financial_services_enterprise_case_management 8.0.7.1 cpe:2.3:a:oracle:financial_services_enterprise_case_management:8.0.7.1:*:*:*:*:*:*:*
oracle financial_services_enterprise_case_management 8.0.7.2 cpe:2.3:a:oracle:financial_services_enterprise_case_management:8.0.7.2:*:*:*:*:*:*:*
oracle financial_services_enterprise_case_management 8.0.8.0 cpe:2.3:a:oracle:financial_services_enterprise_case_management:8.0.8.0:*:*:*:*:*:*:*
oracle financial_services_enterprise_case_management 8.0.8.1 cpe:2.3:a:oracle:financial_services_enterprise_case_management:8.0.8.1:*:*:*:*:*:*:*
oracle financial_services_enterprise_case_management 8.1.1.0 cpe:2.3:a:oracle:financial_services_enterprise_case_management:8.1.1.0:*:*:*:*:*:*:*
oracle financial_services_enterprise_case_management 8.1.1.1 cpe:2.3:a:oracle:financial_services_enterprise_case_management:8.1.1.1:*:*:*:*:*:*:*
oracle primavera_unifier 18.8 cpe:2.3:a:oracle:primavera_unifier:18.8:*:*:*:*:*:*:*
oracle primavera_unifier 19.12 cpe:2.3:a:oracle:primavera_unifier:19.12:*:*:*:*:*:*:*
oracle primavera_unifier 20.12 cpe:2.3:a:oracle:primavera_unifier:20.12:*:*:*:*:*:*:*
oracle primavera_unifier 21.12 cpe:2.3:a:oracle:primavera_unifier:21.12:*:*:*:*:*:*:*

References for CVE-2021-38153

URL Tags
https://kafka.apache.org/cve-list Vendor Advisory
https://lists.apache.org/thread.html/r26390c8b09ecfa356582d665b0c01f4cdcf16ac047c85f9f9f06a88c%40%3Cdev.kafka.apache.org%3E
https://lists.apache.org/thread.html/r26390c8b09ecfa356582d665b0c01f4cdcf16ac047c85f9f9f06a88c%40%3Cusers.kafka.apache.org%3E
https://lists.apache.org/thread.html/r35322aec467ddae34002690edaa4d9f16e7df9b5bf7164869b75b62c%40%3Cdev.kafka.apache.org%3E
https://lists.apache.org/thread.html/r45cc0602d5f2cbb72e48896dfadf5e5b87ed85630449598b40e8f0be%40%3Cdev.kafka.apache.org%3E
https://lists.apache.org/thread.html/r45cc0602d5f2cbb72e48896dfadf5e5b87ed85630449598b40e8f0be%40%3Cusers.kafka.apache.org%3E
https://lists.apache.org/thread.html/rd9ef217b09fdefaf32a4e1835b59b96629542db57e1f63edb8b006e6%40%3Cdev.kafka.apache.org%3E
https://lists.apache.org/thread.html/rd9ef217b09fdefaf32a4e1835b59b96629542db57e1f63edb8b006e6%40%3Cusers.kafka.apache.org%3E
https://www.oracle.com/security-alerts/cpuapr2022.html Patch Third Party Advisory
https://www.oracle.com/security-alerts/cpujan2022.html Third Party Advisory
https://www.oracle.com/security-alerts/cpujul2022.html Third Party Advisory
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