Medium severity · published Apr 9, 2021
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
4.3
CVSS
1.5%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)1.5% · higher than 74% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
DL
Debian Linux · Debian
9.0; 10.0 · source: NVD
FE
Fedora · Fedoraproject
33; 34 · source: NVD
ME
Mediawiki · Mediawiki
before 1.31.12; 1.32.0 before 1.35.2 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-30159
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-30159
Third Party Advisory
https://lists.debian.org/debian-lts-announce/2021/05/msg00003.html
Mailing List
https://lists.debian.org/debian-lts-announce/2021/05/msg00006.html
lists.fedoraproject.org
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/26UJGHF7LJDOCQN6A3Z4PM7PYRKENJHE/
lists.fedoraproject.org
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2OMSV7B2TCFBOCICN3B4SMQP5HVRJQIT/
Exploit
https://phabricator.wikimedia.org/T272386
Third Party Advisory
https://security.gentoo.org/glsa/202107-40
More from Debian Linux
10.0
CVE-2025-32433
Erlang/OTP SSH Vulnerable to Pre-Authentication RCE
10.0
CVE-2025-24201
Apple Multiple Products WebKit Out-of-Bounds Write Vulnerability
10.0
CVE-2021-44228
Apache Log4j2 JNDI features do not protect against attacker controlled LDAP and other JNDI related endpoints
10.0
CVE-2015-3306
ProFTPD Improper Access Control Vulnerability
9.8
CVE-2026-111497
Out-of-Bounds Write in Google Brotli Decoder