Vulnerability in MediaWiki
CVE-2021-30159
An issue was discovered in MediaWiki before 1.31.12 and 1.32.x through 1.35.x before 1.35.2. Users can bypass intended restrictions on deleting pages in certain "fast double move" situations. MovePage::isValidMoveTarget() uses FOR UPDATE, but it's only called if Title::getArticleID() returns non-zero with no special flags. Next, MovePage::moveToInternal() will delete the page if getArticleID(READ_LATEST) is non-zero. Therefore, if the page is missing in the replica DB, isValidMove() will return true, and then moveToInternal() will unconditionally delete the page if it can be found in the master.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N.
EPSS exploit prediction
EPSS: 0.015 (73.6th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 74th percentile — 73.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.016 · newest: 0.015 · change: -0.000
Affected products
- MediaWiki
- Debian Linux — versions 9.0, 10.0
- Fedoraproject Fedora — versions 33, 34
Public proof-of-concept exploits
References
- phabricator.wikimedia.org/T272386 (Exploit, Patch, Vendor Advisory)
- www.debian.org/security/2021/dsa-4889 (vendor-advisory, Third Party Advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/… (vendor-advisory)
- lists.debian.org/debian-lts-announce/2021/05/msg00003.html (mailing-list, Third Party Advisory)
- lists.debian.org/debian-lts-announce/2021/05/msg00006.html (mailing-list, Mailing List, Third Party Advisory)
- security.gentoo.org/glsa/202107-40 (vendor-advisory, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-30159?
- CVE-2021-30159 is a medium-severity vulnerability in MediaWiki. CVSS score: 4.3/10. Published 2021-04-09.
- How severe is CVE-2021-30159?
- Medium severity. CVSS v3 base score is 4.3 out of 10.
- Is CVE-2021-30159 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.