SB2020031406 - Gentoo update for sudo

Description

This security bulletin contains information about 2 secuirty vulnerabilities.

1) Permissions, Privileges, and Access Controls (CVE-ID: CVE-2019-14287)

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists in the implementation of the "sudo" application when processing commands that are configured to run with ALL keyword. A local user with privileges to use sudo for specific applications on the system can escalate privileges and run the application as root (even if precisely restricted), if user id "-1" or "4294967295" is used.

Example:

The following entry instructs sudo to allow user bob to run "/usr/bin/id" command as any user on the system but root:

myhost bob = (ALL, !root) /usr/bin/id

The following command will allow bob execute the  "/usr/bin/id" command as root:

sudo -u#-1 id -u

2) Stack-based buffer overflow (CVE-ID: CVE-2019-18634)

The vulnerability allows a local user to execute arbitrary code on the target system.

The vulnerability exists due to a boundary error within the getln() function in tgetpass.c, if pwfeedback is enabled in /etc/sudoers. A local user can trigger stack-based buffer overflow and execute arbitrary code on the target system with elevated privileges.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Remediation

Install update from vendor's website.

References

• https://security.gentoo.org/
• https://security.gentoo.org/glsa/202003-12