FreeBSD VuXML: Documenting security issues in FreeBSD and the FreeBSD Ports Collection

sudo -- Potential bypass of Runas user restrictions

Affected packages
sudo < 1.8.28

Details

VuXML ID 3a1474ba-f646-11e9-b0af-b888e347c638
Discovery 2019-10-15
Entry 2019-10-24

Todd C. Miller reports:

When sudo is configured to allow a user to run commands as an arbitrary user via the ALL keyword in a Runas specification, it is possible to run commands as root by specifying the user ID -1 or 4294967295.

This can be used by a user with sufficient sudo privileges to run commands as root even if the Runas specification explicitly disallows root access as long as the ALL keyword is listed first in the Runas specification.

Log entries for commands run this way will list the target user as 4294967295 instead of root. In addition, PAM session modules will not be run for the command.

References

CVE Name CVE-2019-14287
URL https://www.sudo.ws/alerts/minus_1_uid.html