Description
An issue was discovered in MediaWiki before 1.35.1. Missing users (accounts that don't exist) and hidden users (accounts that have been explicitly hidden due to being abusive, or similar) that the viewer cannot see are handled differently, exposing sensitive information about the hidden status to unprivileged viewers. This exists on various code paths.
Remediation
References
Related Vulnerabilities
Atlassian Jira Cross-Site Request Forgery (CSRF) Vulnerability (CVE-2019-20411)
MySQL CVE-2019-2819 Vulnerability (CVE-2019-2819)
WebLogic CVE-2020-2549 Vulnerability (CVE-2020-2549)
Plone CMS Weak Password Requirements Vulnerability (CVE-2020-7940)
MediaWiki Resource Management Errors Vulnerability (CVE-2015-2942)