Race condition in apport (Ubuntu package) and python3-apport (Ubuntu package) - CVE-2021-3899

Vulnerability identifier: #VU63360

CSH Severity: Low

CVSS v4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2021-3899

CWE-ID: CWE-362

Exploitation vector: Local access

Exploit availability: Public exploit is available

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

The vulnerability exists due to a race condition in the replaced executable detection. A local user can exploit the race and execute arbitrary code with root privileges.

apport (Ubuntu package)
python3-apport (Ubuntu package)
python-apport (Ubuntu package)
Ubuntu

Install updates from vendor's website.

apport (Ubuntu package) - addressed in versions 2.20.9-0ubuntu7.28, 2.20.11-0ubuntu27.24, 2.20.11-0ubuntu71.2, 2.20.11-0ubuntu82.1, Ubuntu Pro
python3-apport (Ubuntu package) - addressed in versions 2.20.9-0ubuntu7.28, 2.20.11-0ubuntu27.24, 2.20.11-0ubuntu71.2, 2.20.11-0ubuntu82.1, Ubuntu Pro
python-apport (Ubuntu package) - update to Ubuntu Pro

• Exploit #8363 - CVE-2021-3899_PoC (race condition in apport lead to Local Privilege Escalation on Ubuntu) (September 13, 2022)

• https://ubuntu.com/security/notices/USN-5427-1

• Ubuntu update for apport
• Ubuntu update for apport