USN-6719-2: util-linux vulnerability

USN-6719-1 fixed a vulnerability in util-linux. Unfortunately, it was
discovered that the fix did not fully address the issue. This update
removes the setgid permission bit from the wall and write utilities.

Original advisory details:

Skyler Ferrante discovered that the util-linux wall command did not filter
escape sequences from command line arguments. A local attacker could
possibly use this issue to obtain sensitive information.

address advisory attacker command command line escape filter fix issue line linux linux vulnerability local permission update usn utilities vulnerability wall