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.

EPSS: 0.016 (72.7th percentile) — read the EPSS interpretation.

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.

Affected products

Public proof-of-concept exploits

References

  • cve@mitre.org (Exploit, Patch, x_refsource_MISC, Vendor Advisory)
  • cve@mitre.org (vendor-advisory, Third Party Advisory, x_refsource_DEBIAN)
  • cve@mitre.org (x_refsource_FEDORA, vendor-advisory)
  • cve@mitre.org (x_refsource_FEDORA, vendor-advisory)
  • cve@mitre.org (mailing-list, x_refsource_MLIST, Third Party Advisory)
  • cve@mitre.org (mailing-list, x_refsource_MLIST, Mailing List, Third Party Advisory)
  • cve@mitre.org (vendor-advisory, Third Party Advisory, x_refsource_GENTOO)

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.