SB2021041203 - Debian update for mediawiki
Published: April 12, 2021
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 8 secuirty vulnerabilities.
1) Infinite loop (CVE-ID: CVE-2021-20270)
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to infinite loop. A remote attacker can consume all available system resources and cause denial of service conditions.
2) Resource management error (CVE-ID: CVE-2021-27291)
The vulnerability allows a remote attacker to perform a denial of service (ReDoS) attack.
The vulnerability exists due to improper management of internal resources within the application. A remote attacker can pass specially crafted data to the application and perform regular expression denial of service (ReDoS) attack.
3) Security restrictions bypass (CVE-ID: CVE-2021-30152)
The vulnerability allows a remote user to escalate privileges on the system.
The vulnerability exists due to application does not properly impose security restrictions within MediaWiki API. A remote authenticated user can apply "protect" feature for pages to a higher level than they currently have permissions for.
4) Improper access control (CVE-ID: CVE-2021-30159)
The vulnerability allows a remote user to gain unauthorized access to otherwise restricted functionality.
The vulnerability exists due to improper access restrictions. 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.
5) Cross-site scripting (CVE-ID: CVE-2021-30154)
The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.
The vulnerability exists due to insufficient sanitization of user-supplied data within "Special:NewFiles". A remote attacker can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in user's browser in context of vulnerable website.
Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.
6) Improper access control (CVE-ID: CVE-2021-30155)
The vulnerability allows a remote user to gain unauthorized access to otherwise restricted functionality.
The vulnerability exists due to improper access restrictions within ContentModelChange, which does not check if a user has correct permissions to create and set the content model of a nonexistent page. A remote user can bypass implemented security restrictions and gain unauthorized access to the application.
7) Cross-site scripting (CVE-ID: CVE-2021-30157)
The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.
The vulnerability exists due to insufficient sanitization of user-supplied data on ChangesList special pages, such as Special:RecentChanges and Special:Watchlist. A remote attacker can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in user's browser in context of vulnerable website.
Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.
8) Improper access control (CVE-ID: CVE-2021-30158)
The vulnerability allows a remote attacker to gain unauthorized access to otherwise restricted functionality.
The vulnerability exists due to improper access restrictions, related to usage of Special:ResetTokens by blocked users. A remote attacker can reset access token and gain unauthorized access to the application.
Remediation
Install update from vendor's website.