MediawikiCMS

CVE-2021-45038

MEDIUM · 5.3 CVSS v3.1 Published 2021-12-17
Fix available
A fix is available. Upgrade to 1.35.5 / 1.36.3 or later.
See remediation →
62/100
Remediation priority · Elevated
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
An issue was discovered in MediaWiki before 1.35.5, 1.36.x before 1.36.3, and 1.37.x before 1.37.1. By using an action=rollback query, attackers can view private wiki contents.

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

MediaWiki versions before 1.35.5, 1.36.3, and 1.37.1 contain an information disclosure vulnerability where the action=rollback query parameter can be exploited to view private wiki contents that should be restricted to authorized users.

MitigationUpgrade MediaWiki to version 1.35.5, 1.36.3, 1.37.1 or later to apply the security patch that fixes the unauthorized content disclosure via rollback queries.

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
MediawikiCMS
Affected:< 1.35.5>= 1.36.0, < 1.36.3>= 1.37.0, < 1.37.1

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
Low
Integrity
None
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/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. Check MediaWiki version
    Open includes/Defines.php or includes/AutoLoader.php and look for the $wgVersion variable, or query the API at /api.php?action=query&meta=siteinfo&siprop=general
    Affected if The installed version is less than 1.35.5, OR between 1.36.0 and 1.36.2 inclusive, OR between 1.37.0 and 1.37.0 inclusive
  2. Verify rollback feature is accessible
    Confirm the wiki has users with rollback rights by checking Special:ListGroupRights or reviewing $wgGroupPermissions in LocalSettings.php for the 'rollback' permission
    Affected if The rollback feature is granted to any user role (even restricted ones) on the wiki
  3. Confirm private content exists
    Review whether the wiki contains restricted pages, such as those protected with 'autoconfirmed' or higher protection levels, or pages in restricted namespaces
    Affected if The wiki hosts content that should be visible only to authorized users and the version is in the affected range

If the installed MediaWiki version falls within the affected ranges (< 1.35.5, 1.36.0-1.36.2, or 1.37.0) AND the wiki contains restricted content accessible to users with rollback rights, the environment is vulnerable to CVE-2021-45038.

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 1.35.5 / 1.36.3 / 1.37.1 or later
Fixed in 1.35.51.36.31.37.1
Interim mitigation

Upgrade MediaWiki to version 1.35.5, 1.36.3, 1.37.1 or later to apply the security patch that fixes the unauthorized content disclosure via rollback queries.

Recommended fix High confidence

1.35.5, 1.36.3, or 1.37.1 (or latest stable 1.38.x)

  1. 1. Create a full backup of your MediaWiki database
  2. 2. Create a full backup of your MediaWiki files and configuration
  3. 3. Download the appropriate MediaWiki release (1.35.5, 1.36.3, or 1.37.1 or later) from www.mediawiki.org
  4. 4. Extract the new MediaWiki files and replace the existing installation files
  5. 5. Run the maintenance/update.php script to apply database schema changes: php maintenance/update.php
  6. 6. Clear all MediaWiki caches (can be done via maintenance script or admin interface)
  7. 7. Verify the installation is working and the vulnerability is resolved
Caveat Patch version upgrades (e.g., 1.35.4 to 1.35.5) typically have minimal breaking changes; always review the release notes before upgrading

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

Fix this in Mediawiki Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,040
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,664.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-45038 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

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-2021-45038 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