Auth bypass in MediaWiki
CVE-2021-31552
An issue was discovered in the AbuseFilter extension for MediaWiki through 1.35.2. It incorrectly executed certain rules related to blocking accounts after account creation. Such rules would allow for user accounts to be created while blocking only the IP address used to create an account (and not the user account itself). Such rules could also be used by a nefarious, unprivileged user to catalog and enumerate any number of IP addresses related to these account creations.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N.
EPSS exploit prediction
EPSS: 0.006 (45.4th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 45th percentile — 45.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000
Affected products
Weakness classification (CWE)
References
- phabricator.wikimedia.org/T152394 (Third Party Advisory)
- gerrit.wikimedia.org/r/q/I8bae477ad7e4d0190335363ac2decf28e4313da1 (Issue Tracking, Vendor Advisory)
Frequently asked questions
- What is CVE-2021-31552?
- CVE-2021-31552 is a medium-severity vulnerability in MediaWiki, classified under Incorrect Authorization. CVSS score: 5.4/10. Published 2021-04-22.
- How severe is CVE-2021-31552?
- Medium severity. CVSS v3 base score is 5.4 out of 10.