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GitLabApplication

CVE-2020-13300

CRITICAL · 10.0 CVSS v3.1 Published 2020-09-14
Fix available
A fix is available. Upgrade to 13.3.4 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
GitLab CE/EE version 13.3 prior to 13.3.4 was vulnerable to an OAuth authorization scope change without user consent in the middle of the authorization flow.

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 · high confidence

GitLab CE/EE versions 13.3 before 13.3.4 contained an OAuth authorization flaw allowing scope changes without user consent during the authorization flow. An attacker could manipulate the OAuth scope parameter mid-authorization to request additional permissions the user did not initially approve, potentially gaining unauthorized access to resources.

MitigationUpgrade GitLab to version 13.3.4 or later. Review existing OAuth authorizations for any unexpected scope grants and consider revoking and re-authorizing sensitive integrations.

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:>= 13.3.0, < 13.3.4

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
Changed
Confidentiality
High
Integrity
High
Availability
None

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

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 `gitlab-rake gitlab:env:info` or check `/opt/gitlab/version` to obtain the exact GitLab version number. Alternatively, visit the GitLab Admin area dashboard which displays the version at the bottom.
    Affected if The version shown is 13.3.0, 13.3.1, 13.3.2, or 13.3.3 (any version from 13.3.0 up to but not including 13.3.4)
  2. Verify OAuth feature is enabled
    Navigate to Admin Area > Settings > OAuth or check the gitlab_rails['gitlab_oauth_enabled'] setting in /etc/gitlab/gitlab.rb. You can also query the database: `SELECT * FROM applications WHERE OAuth IS NOT NULL LIMIT 1;`
    Affected if OAuth is enabled and at least one OAuth application exists in the GitLab instance
  3. Review existing OAuth authorizations
    As an administrator, review the OAuth applications list in Admin Area > Applications. Check for any applications with scopes that seem unexpected or overly broad compared to what was originally intended.
    Affected if There are OAuth applications with scopes that differ from what users expected to authorize, or any application with elevated scopes not originally requested
  4. Check audit logs for OAuth authorization events
    Navigate to Admin Area > Monitoring > Audit Events and filter by event type 'OAuth' or query the audit_events table for oauth_authorize events. Look for rapid or duplicate authorization requests.
    Affected if Audit logs show OAuth authorization events with scope parameters that changed during the authorization flow, or duplicate authorization requests for the same user/application

A GitLab instance is affected if it runs any version from 13.3.0 through 13.3.3 and has OAuth enabled with active OAuth applications, particularly if audit events show scope parameter anomalies.

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 13.3.4 or later
Fixed in 13.3.4
Interim mitigation

Upgrade GitLab to version 13.3.4 or later. Review existing OAuth authorizations for any unexpected scope grants and consider revoking and re-authorizing sensitive integrations.

Recommended fix High confidence

13.3.4

  1. Back up your GitLab instance data and configuration
  2. Ensure you have a way to restore from backup if needed
  3. Follow GitLab's official upgrade documentation for your installation method (package manager, Docker, source)
  4. Upgrade GitLab to version 13.3.4
  5. Verify the upgrade was successful by checking the GitLab version in the admin area
  6. Test OAuth functionality to confirm the vulnerability is remediated

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

Fix this in GitLab Scoped from the published advisory
  • Consultation4.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA3.0 h
17.0 hours of engineering $2,960
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,736.

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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-2020-13300 in production — separate from our analysis above.

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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