CVE-2012-5391
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 · uneditedSession fixation vulnerability in Special:UserLogin in MediaWiki before 1.18.6, 1.19.x before 1.19.3, and 1.20.x before 1.20.1 allows remote attackers to hijack web sessions via the session_id.
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 confidenceSession fixation vulnerability in MediaWiki's login page (Special:UserLogin) allows remote attackers to manipulate or set the session_id parameter, enabling them to hijack authenticated user sessions by predetermining the session identifier that victims will use after logging in.
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<= 1.18.5= 1.18= 1.18.0= 1.18.1= 1.18.2= 1.18.3= 1.18.4= 1.19= 1.19.1= 1.19.2= 1.20CVSS 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
- M
- Authentication
- None
- Confidentiality
- Partial
- Integrity
- Partial
- Availability
- Partial
AV:N/AC:M/Au:N/C:P/I:P/A:P
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 checksWork through these to decide whether this CVE applies to you.
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Locate MediaWiki installation and version fileCheck the file includes/Defines.php in your MediaWiki root directory. Look for a line defining MW_VERSION or similar version constant, or check the file LocalSettings.php for version information.Affected if The version number found is 1.18.0 through 1.18.5, 1.18, 1.19.0 through 1.19.2, 1.19, or 1.20 (any version listed in the affected products range).
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Verify login page is accessibleConfirm that Special:UserLogin is accessible on your MediaWiki instance by accessing the login URL (usually /index.php?title=Special:UserLogin or /wiki/Special:UserLogin).Affected if The login page responds normally, indicating the vulnerable login component is active.
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Check session handling configurationInspect the LocalSettings.php file in your MediaWiki root directory for session-related configuration. Look for $wgSessionName or session settings. Also check if the default PHP session handling is in use.Affected if The site uses default session handling without custom session ID regeneration on login, which is the vulnerable configuration present in affected versions.
You are affected if your MediaWiki installation version falls within 1.18.0-1.18.5, 1.19.0-1.19.2, or 1.20 and the login page is accessible.
Generated from the published advisory. Verify against your own configuration.
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.
From vendor dataUpgrade MediaWiki to version 1.18.6, 1.19.3, or 1.20.1 or later to obtain the patched session handling code that properly regenerates session IDs upon authentication.
- Consultation3.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,408.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2012-5391 — 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 sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2012-5391 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- 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
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