Debian LinuxOperating system · Debian
CVE-2020-35480
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 · uneditedAn issue was discovered in MediaWiki before 1.35.1. Missing users (accounts that don't exist) and hidden users (accounts that have been explicitly hidden due to being abusive, or similar) that the viewer cannot see are handled differently, exposing sensitive information about the hidden status to unprivileged viewers. This exists on various code paths.
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 confidenceIn MediaWiki before 1.35.1, the software handles missing users (non-existent accounts) and hidden users (accounts hidden due to abuse) differently in various code paths. This inconsistency allows unprivileged viewers to distinguish between the two cases, thereby exposing whether a specific username has been hidden by administrators—a sensitive administrative setting that should remain confidential.
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
Debian LinuxOperating system
= 9.0= 10.0
FedoraOperating system
= 33< 1.35.1CVSS 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 checksWork through these to decide whether this CVE applies to you.
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Verify MediaWiki is installedLook for MediaWiki installation directories (commonly /var/www/html/wiki, /w, or similar) or check for includes/Defines.php file which contains version informationAffected if MediaWiki software is found on the system
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Determine installed MediaWiki versionOpen includes/Defines.php and locate the MW_VERSION constant, or check the version file in the root installation directoryAffected if The version string indicates a release prior to 1.35.1
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Confirm user lookup functionality is accessibleTest if the Special:UserLogin or API queries that perform user lookups (such as action=query&list=users) are accessible to anonymous or unprivileged authenticated users without special rightsAffected if Unprivileged users can query user accounts through the web interface or API
If MediaWiki version is below 1.35.1 and unprivileged user lookup queries are permitted, the environment is affected by CVE-2020-35480.
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 data1.35.1
Upgrade MediaWiki to version 1.35.1 or later. Alternatively, audit and modify all code paths that handle user lookups to treat missing and hidden users identically when presented to unprivileged users.
Fix this in Debian Linux
Scoped from the published advisory
- Consultation2.0 h
- Implementation6.0 h
- Testing4.0 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 $3,904.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-35480 — 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-2020-35480 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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