SB2021012716 - Gentoo update for sudo

Description

This security bulletin contains information about 3 secuirty vulnerabilities.

1) Link following (CVE-ID: CVE-2021-23239)

The vulnerability allows a local authenticated user to gain access to sensitive information.

The sudoedit personality of Sudo before 1.9.5 may allow a local unprivileged user to perform arbitrary directory-existence tests by winning a sudo_edit.c race condition in replacing a user-controlled directory by a symlink to an arbitrary path.

2) Link following (CVE-ID: CVE-2021-23240)

The vulnerability allows a local authenticated user to execute arbitrary code.

selinux_edit_copy_tfiles in sudoedit in Sudo before 1.9.5 allows a local unprivileged user to gain file ownership and escalate privileges by replacing a temporary file with a symlink to an arbitrary file target. This affects SELinux RBAC support in permissive mode. Machines without SELinux are not vulnerable.

3) Heap-based buffer overflow (CVE-ID: CVE-2021-3156)

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

The vulnerability exists due to a boundary error in sudo. A local user can pass specially crafted data to the application, trigger heap-based buffer overflow and execute arbitrary code on the target system with root privileges.

Remediation

Install update from vendor's website.

References

• https://security.gentoo.org/
• https://security.gentoo.org/glsa/202101-33