Security readout for executives and security teams
Plain-English summary
CVE-2021-38153 is a timing weakness in Apache Kafka credential checks. Certain Kafka components compared passwords or keys in a way that could leak small timing differences, making brute force attempts more practical under the right conditions.
Executive priority
Prioritize remediation for Kafka systems handling sensitive data, exposed to broad internal networks, or using shared service credentials. The main business risk is improved credential guessing, not direct remote code execution based on the provided sources.
Technical view
Apache Kafka versions 2.0.0 through 2.8.0 used Arrays.equals in some password or key validation paths. That comparison can return timing differences based on matched bytes, a CWE-203 observable discrepancy. Apache says the issue is fixed in 2.8.1 or higher, and 3.0.0 or higher.
Likely exposure
Exposure is most likely where affected Kafka Connect or Kafka client components are deployed and an attacker can repeatedly trigger credential validation while measuring response timing. Inventory should include direct Kafka deployments, bundled Kafka distributions, and applications carrying affected Kafka client libraries.
Exploitation context
The bundle does not show CISA KEV listing or cited active exploitation. Practical exploitation depends on repeated attempts, measurable timing signals, and valid access to a relevant validation path. Treat it as a credential-risk issue, not confirmed internet-wide exploitation.
Researcher notes
Evidence is limited to the CVE description, Apache CVE listing, and release/backport mailing-list references. No CVSS vector is provided in the bundle. Do not assume fixed backport versions beyond the stated 2.8.1+ or 3.0.0+ guidance without vendor confirmation.
Mitigation direction
- Upgrade Apache Kafka to 2.8.1 or higher, or 3.0.0 or higher.
- Identify applications using affected Kafka client libraries and update those dependencies.
- Check downstream vendor advisories for bundled Kafka fixes and supported upgrade paths.
- Reduce unnecessary network access to Kafka Connect, brokers, and client-facing services.
- Investigate credential abuse if logs show unusual repeated authentication attempts.
Validation and detection
- Confirm no Kafka runtime reports version 2.0.0 through 2.8.0.
- Review dependency manifests and container images for affected Kafka client versions.
- Verify Kafka Connect workers and client applications use fixed Kafka packages.
- Check authentication logs for repeated failed attempts against Kafka-related services.
- Document any vendor-packaged Kafka instances and their advisory status.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-203: Information exposure and cloud metadata lookup
Information exposure and SSRF weaknesses can make discovery, cloud metadata, and credential material review relevant. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCredential and access behavior lookup
The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-38153 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://kafka.apache.org/cve-listCVE reference · x_refsource_MISC
- [kafka-dev] 20211007 Re: CVE Back Port?CVE reference · mailing-list, x_refsource_MLIST
- [kafka-dev] 20211012 [VOTE] 2.6.3 RC0CVE reference · mailing-list, x_refsource_MLIST
- [kafka-users] 20211012 [VOTE] 2.6.3 RC0CVE reference · mailing-list, x_refsource_MLIST
- [kafka-users] 20211012 [VOTE] 2.7.2 RC0CVE reference · mailing-list, x_refsource_MLIST
- [kafka-dev] 20211012 [VOTE] 2.7.2 RC0CVE reference · mailing-list, x_refsource_MLIST
- [kafka-users] 20211026 Re: [kafka-clients] [VOTE] 2.7.2 RC0CVE reference · mailing-list, x_refsource_MLIST
- [kafka-dev] 20211026 Re: [kafka-clients] [VOTE] 2.7.2 RC0CVE reference · mailing-list, x_refsource_MLIST
- https://www.oracle.com/security-alerts/cpujan2022.htmlCVE reference · x_refsource_MISC
- https://www.oracle.com/security-alerts/cpuapr2022.htmlCVE reference · x_refsource_MISC
- https://www.oracle.com/security-alerts/cpujul2022.htmlCVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Observable Discrepancy
Observable Discrepancy represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.