Auth bypass in MediaWiki
CVE-2020-26121
An issue was discovered in the FileImporter extension for MediaWiki before 1.34.4. An attacker can import a file even when the target page is protected against "page creation" and the attacker should not be able to create it. This occurs because of a mishandled distinction between an upload restriction and a create restriction. An attacker cannot leverage this to overwrite anything, but can leverage this to force a wiki to have a page with a disallowed title.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.
EPSS exploit prediction
EPSS: 0.013 (68.9th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 69th percentile — 68.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.013 · newest: 0.013 · change: 0.000
Affected products
- MediaWiki
- Fedoraproject Fedora — versions 33
Weakness classification (CWE)
References
- commons.wikimedia.org/w/index.php (Vendor Advisory)
- phabricator.wikimedia.org/T262628 (Patch, Issue Tracking, Vendor Advisory)
- gerrit.wikimedia.org/r/q/Ib852a96afc4dca10516d0510e69c10f9892b351b (Patch, Vendor Advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
Frequently asked questions
- What is CVE-2020-26121?
- CVE-2020-26121 is a high-severity vulnerability in MediaWiki, classified under Incorrect Authorization. CVSS score: 7.5/10. Published 2020-09-27.
- How severe is CVE-2020-26121?
- High severity. CVSS v3 base score is 7.5 out of 10.