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GitLabApplication

CVE-2021-39893

HIGH · 7.5 CVSS v3.1 Published 2021-10-05
Fix available
A fix is available. Upgrade to 14.1.7 / 14.2.5 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A potential DOS vulnerability was discovered in GitLab starting with version 9.1 that allowed parsing files without authorisation.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

A potential denial-of-service vulnerability in GitLab starting version 9.1 allowed parsing files without proper authorization. This could enable an unauthenticated attacker to trigger excessive resource consumption or access file parsing functionality beyond their intended permissions.

MitigationUpgrade GitLab to the latest version containing the security patch for CVE-2021-39893 to remediate the unauthorized file parsing and potential DOS condition.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
GitLabApplication
Affected:>= 9.1.0, < 14.1.7>= 14.2.0, < 14.2.5>= 14.3.0, < 14.3.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed GitLab version
    Run command: `gitlab-rake gitlab:env:info` or check `/opt/gitlab/version-manifest.txt` or use `gitlab-ctl version`
    Affected if The version shown does not fall into the safe ranges: 14.1.7+, 14.2.5+, 14.3.1+, or versions prior to 9.1.0
  2. Confirm GitLab edition and package version
    Check the package manager output: `dpkg -l | grep gitlab` (Debian/Ubuntu) or `rpm -qa | grep gitlab` (RHEL/CentOS)
    Affected if The installed package version matches the affected ranges: >= 9.1.0 and < 14.1.7, OR >= 14.2.0 and < 14.2.5, OR >= 14.3.0 and < 14.3.1
  3. Verify file parsing endpoint exposure
    Review GitLab external web configuration and confirm whether unauthenticated file import/parsing endpoints are accessible to the internet
    Affected if Unauthenticated file parsing endpoints are exposed externally and the GitLab version falls within the affected ranges

The environment is affected if the installed GitLab version falls within any of these ranges: >= 9.1.0 and < 14.1.7, OR >= 14.2.0 and < 14.2.5, OR >= 14.3.0 and < 14.3.1.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 14.1.7 / 14.2.5 / 14.3.1 or later
Fixed in 14.1.714.2.514.3.1
Interim mitigation

Upgrade GitLab to the latest version containing the security patch for CVE-2021-39893 to remediate the unauthorized file parsing and potential DOS condition.

Recommended fix High confidence

Upgrade to GitLab 14.3.1 or later (14.1.7+ if staying in 14.1.x line, 14.2.5+ if staying in 14.2.x line)

  1. 1. Back up your GitLab instance data and configuration before upgrading
  2. 2. Check the current GitLab version by running `gitlab-rake gitlab:env:info`
  3. 3. Determine your upgrade path based on your current version - follow GitLab's recommended upgrade path documentation
  4. 4. For major version jumps (e.g., from 12.x to 14.x), upgrade incrementally through major versions
  5. 5. Run the official GitLab upgrade command for your installation method (e.g., `apt-get update && apt-get install gitlab-ee` for Debian/Ubuntu, or `yum install gitlab-ee` for RHEL/CentOS)
  6. 6. After upgrade, run `gitlab-ctl reconfigure` to apply configuration
  7. 7. Verify the upgrade was successful by checking the version with `gitlab-rake gitlab:env:info`
  8. 8. Confirm the GitLab instance is operational and the vulnerability is resolved
Caveat Review GitLab upgrade notes for potential breaking changes between your current version and target version, especially for major version upgrades

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in GitLab Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,088.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-39893 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data