Ubuntu Security Notice 401-1 – It was discovered that local users could delete other users’ D-Bus match rules. Applications would stop receiving D-Bus messages, resulting in a local denial of service, and potential data loss for applications that depended on D-Bus for storing information.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/53447/USN-401-1.txt
Source: https://packetstormsecurity.com/files/53447/Ubuntu-Security-Notice-401-1.html