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GitLabApplication

CVE-2018-8971

CRITICAL · 9.8 CVSS v3.0 Published 2018-03-24
Fix available
A fix is available. Upgrade to after 10.5.5 or later.
See remediation →
100/100
Remediation priority · Urgent
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
The Auth0 integration in GitLab before 10.3.9, 10.4.x before 10.4.6, and 10.5.x before 10.5.6 has an incorrect omniauth-auth0 configuration, leading to signing in unintended users.

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

The Auth0 omniauth integration in affected GitLab versions has an incorrect configuration that allows authentication of unintended users, potentially enabling unauthorized access to arbitrary user accounts through the SSO flow.

MitigationUpgrade GitLab to version 10.3.9, 10.4.6, or 10.5.6 or later to obtain the corrected omniauth-auth0 configuration.

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:<= 10.3.8>= 10.4.0, <= 10.4.5>= 10.5.0, <= 10.5.5
Debian LinuxOperating system
Affected:= 9.0

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
High
Integrity
High
Availability
High

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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. Determine installed GitLab version
    Run `gitlab-rake gitlab:env:info` or check the GitLab admin interface at /admin/about. Alternatively, check /opt/gitlab/embedded/lib/ruby/gems/*/gems/gitlab-*/VERSION file.
    Affected if The displayed version falls within <= 10.3.8; >= 10.4.0 and <= 10.4.5; or >= 10.5.0 and <= 10.5.5.
  2. Verify Auth0 omniauth is configured
    Check GitLab configuration file (typically /etc/gitlab/gitlab.rb) for lines containing 'omniauth' and 'auth0'. Also check the GitLab admin panel under Administration > Settings > Authentication (OmniAuth providers).
    Affected if Auth0 is listed as an enabled OmniAuth provider.
  3. Confirm SSO flow is active
    Review the Auth0 provider configuration to verify that 'allow_single_sign_on' or 'auto_link_user' attributes are set, which enable the SSO authentication flow.
    Affected if SSO authentication with Auth0 is actively enabled for user sign-in.

You are affected if you run a vulnerable GitLab version (10.3.x through 10.5.5) with Auth0 OmniAuth SSO enabled, as the configuration flaw can allow authentication of unintended users to arbitrary accounts.

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 a release after 10.5.5
Interim mitigation

Upgrade GitLab to version 10.3.9, 10.4.6, or 10.5.6 or later to obtain the corrected omniauth-auth0 configuration.

Recommended fix High confidence

GitLab 10.3.9, 10.4.6, 10.5.6, or latest 10.x stable (11.x+ recommended for security)

  1. 1. Identify the currently installed GitLab version using `sudo gitlab-rake gitlab:env:info`
  2. 2. For GitLab 10.3.x (10.3.0-10.3.8): Upgrade to GitLab 10.3.9 or later (recommended: 10.5.6 or latest 10.x stable)
  3. 3. For GitLab 10.4.x (10.4.0-10.4.5): Upgrade to GitLab 10.4.6 or later (recommended: 10.5.6 or latest 10.x stable)
  4. 4. For GitLab 10.5.x (10.5.0-10.5.5): Upgrade to GitLab 10.5.6 or later (recommended: latest 10.x stable)
  5. 5. For Debian 9.0 with packaged GitLab: Update package lists with `apt update` and upgrade GitLab via `apt upgrade` or install the updated package
  6. 6. After upgrade, verify the omniauth-auth0 configuration in /etc/gitlab/gitlab.rb or gitlab.yml to ensure it uses the correct Auth0 tenant URL and callback settings
  7. 7. Reconfigure GitLab with `sudo gitlab-ctl reconfigure` after any configuration changes
  8. 8. Test the Auth0 authentication flow to confirm the fix is working correctly
Caveat Minor: Review omniauth configuration after upgrade; GitLab 10.x to 11.x may require additional database migrations - test in staging first

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
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
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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-2018-8971 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