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

EPSS: 0.013 (67.0th percentile) — read the EPSS interpretation.

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.

Affected products

Weakness classification (CWE)

References

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.