CVE-2012-5395
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 the CentralAuth extension for 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 centralauth_Session cookie.
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 CentralAuth extension allows remote attackers to hijack web sessions by manipulating the centralauth_Session cookie. Attackers can set a known session ID before user authentication, then use that same ID to impersonate the user after login.
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= 1.20= 1.19= 1.19.1= 1.19.2<= 1.18.5= 1.18= 1.18.0= 1.18.1= 1.18.2= 1.18.3= 1.18.4CVSS 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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Identify installed MediaWiki versionCheck the $wgVersion variable in your LocalSettings.php file, or access Special:Version on your wikiAffected if The installed version is 1.18.0 through 1.18.5, 1.19, 1.19.1, 1.19.2, or 1.20.0
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Confirm CentralAuth extension is enabledLook for require_once or wfLoadExtension calls for CentralAuth in your LocalSettings.php configuration fileAffected if CentralAuth extension is loaded and enabled in the wiki configuration
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Verify session cookie configurationInspect HTTP headers when accessing the wiki login page, specifically look for the centralauth_Session cookie being set before authenticationAffected if The centralauth_Session cookie is present and can be set by an attacker prior to authentication
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Check session ID behavior on loginSet a known value for the centralauth_Session cookie, then authenticate and observe whether the same session ID is retained after successful loginAffected if The session ID remains unchanged after user authentication (no session regeneration occurs)
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Review session configuration settingsExamine $wgSessionInDatabase, $wgCentralAuthSessionAutoLogin, and related session settings in LocalSettings.phpAffected if Database sessions are not enabled or CentralAuth auto-login is configured in a way that allows pre-authentication session fixation
Your wiki is affected if it runs MediaWiki versions 1.18.0-1.18.5, 1.19-1.19.2, or 1.20.0 with the CentralAuth extension enabled and without session ID regeneration on authentication.
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, 1.20.1 or later. Consider implementing session ID regeneration on authentication as a defense-in-depth measure.
- Consultation3.0 h
- Implementation4.0 h
- Testing6.0 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 $4,128.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2012-5395 — 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-2012-5395 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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