An Ubuntu-specific modification to AccountsService in versions before 0.6.55-0ubuntu13.2, among other earlier versions, improperly dropped the ruid, allowing untrusted users to send signals to AccountService, thus stopping it from handling D-Bus messages in a timely fashion.
Source: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-16126
Reference (s):
- https://securitylab.github.com/advisories/GHSL-2020-187-accountsservice-drop-privs-DOS
- URL: https://securitylab.github.com/advisories/GHSL-2020-187-accountsservice-drop-privs-DOS