Vulnerability Name:

CVE-2021-31553 (CCN-200579)

Assigned:2021-02-24
Published:2021-02-24
Updated:2021-04-22
Summary:An issue was discovered in the CheckUser extension for MediaWiki through 1.35.2. MediaWiki usernames with trailing whitespace could be stored in the cu_log database table such that denial of service occurred for certain CheckUser extension pages and functionality. For example, the attacker could turn off Special:CheckUserLog and thus interfere with usage tracking.
CVSS v3 Severity:6.5 Medium (CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L)
5.7 Medium (Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): None
Integrity (I): Low
Availibility (A): Low
6.5 Medium (CCN CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L)
5.7 Medium (CCN Temporal CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L/E:U/RL:O/RC:C)
Exploitability Metrics:Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope:Scope (S): Unchanged
Impact Metrics:Confidentiality (C): None
Integrity (I): Low
Availibility (A): Low
CVSS v2 Severity:6.4 Medium (CVSS v2 Vector: AV:N/AC:L/Au:N/C:N/I:P/A:P)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Authentication (Au): None
Impact Metrics:Confidentiality (C): None
Integrity (I): Partial
Availibility (A): Partial
6.4 Medium (CCN CVSS v2 Vector: AV:N/AC:L/Au:N/C:N/I:P/A:P)
Exploitability Metrics:Access Vector (AV): Network
Access Complexity (AC): Low
Athentication (Au): None
Impact Metrics:Confidentiality (C): None
Integrity (I): Partial
Availibility (A): Partial
Vulnerability Type:CWE-428
Vulnerability Consequences:Denial of Service
References:Source: MITRE
Type: CNA
CVE-2021-31553

Source: XF
Type: UNKNOWN
mediawiki-cve202131553-dos(200579)

Source: CCN
Type: Phabricator T275669
Checkuser stores users to cu_log with trailing spaces, allowing all CUs to turn off Special:CheckuserLog at will

Vulnerable Configuration:Configuration CCN 1:
  • cpe:/a:mediawiki:mediawiki:1.35.2:*:*:*:*:*:*:*

    • * Denotes that component is vulnerable
    BACK
    mediawiki mediawiki 1.35.2