dbcve.org
FedoraOperating system · Fedoraproject

CVE-2023-29141

CRITICAL · 9.8 CVSS v3.1 Published 2023-03-31
Fix available
A fix is available. Upgrade to 1.35.10 / 1.38.6 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
An issue was discovered in MediaWiki before 1.35.10, 1.36.x through 1.38.x before 1.38.6, and 1.39.x before 1.39.3. An auto-block can occur for an untrusted X-Forwarded-For header.

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

MediaWiki's auto-block feature uses the X-Forwarded-For HTTP header to identify users for blocking. Since this header can be spoofed by an attacker, remote attackers can manipulate it to cause false auto-blocks on arbitrary IP addresses, leading to denial of service for legitimate users or potential bypass of IP-based restrictions.

MitigationUpgrade to MediaWiki 1.35.10, 1.38.6, 1.39.3 or later, or properly configure the $wgTrustProxy and $wgProxyList settings to validate X-Forwarded-For headers from trusted sources only.

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
FedoraOperating system
Affected:= 37
MediawikiCMS
Affected:< 1.35.10>= 1.36.0, < 1.38.6>= 1.39.0, < 1.39.3

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:3.1/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 MediaWiki version
    Check the version file in your MediaWiki installation (usually includes/Version.php or the Special:Version page)
    Affected if Version is < 1.35.10, or >= 1.36.0 and < 1.38.6, or >= 1.39.0 and < 1.39.3
  2. Locate MediaWiki configuration file
    Find the LocalSettings.php file in your MediaWiki installation root directory
    Affected if The LocalSettings.php file exists and is readable
  3. Check if $wgTrustProxy is configured
    Search for $wgTrustProxy in LocalSettings.php and verify if it is set to true or to a specific list of trusted IP addresses
    Affected if $wgTrustProxy is not set or is set to false, meaning X-Forwarded-For headers are not validated from trusted sources
  4. Check if $wgProxyList is configured
    Search for $wgProxyList in LocalSettings.php and verify if it contains a list of trusted proxy IP addresses
    Affected if $wgProxyList is not defined or is empty, meaning no proxy whitelist exists to validate X-Forwarded-For headers
  5. Verify auto-block feature status
    Check if the auto-block feature is enabled in MediaWiki by looking for $wgAutoBlockOnIpBlock in LocalSettings.php (default is true)
    Affected if $wgAutoBlockOnIpBlock is not explicitly set to false, meaning auto-blocking via X-Forwarded-For is active

You are affected if your MediaWiki version falls within the vulnerable ranges AND the auto-block feature is enabled without proper $wgTrustProxy or $wgProxyList configuration to validate X-Forwarded-For headers from trusted sources.

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 1.35.10 / 1.38.6 / 1.39.3 or later
Fixed in 1.35.101.38.61.39.3
Interim mitigation

Upgrade to MediaWiki 1.35.10, 1.38.6, 1.39.3 or later, or properly configure the $wgTrustProxy and $wgProxyList settings to validate X-Forwarded-For headers from trusted sources only.

Recommended fix High confidence

MediaWiki 1.39.3 (LTS) or later; alternatively 1.38.6+ or 1.35.10+

  1. Back up your MediaWiki database and files before upgrading
  2. Download MediaWiki version 1.39.3 or later (recommended), or version 1.38.6+, or version 1.35.10+
  3. Extract the new MediaWiki files to your web server document root
  4. Run the update.php maintenance script: php maintenance/update.php
  5. Clear any caches and verify the installation works correctly
Caveat Minor release upgrades typically have no breaking changes, but review release notes before upgrading across major versions

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

Fix this in Fedora 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

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Scan for this in your stack

Free · runs locally
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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-2023-29141 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