Privilege escalation in systemd

1) Use-after-free

EUVDB-ID: #VU25332

Risk: Low

CVSSv3.1: 8.1 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:U/RL:U/RC:C]

CVE-ID: CVE-2020-1712

CWE-ID: CWE-416 - Use After Free

Exploit availability: No

Description

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

The vulnerability exists due to a use-after-free error when processing dbus messages during asynchronous Polkit queries in bus-polkit.c in systemd. A local unprivileged user can send a specially crafted dbus message, trigger a use-after-free error and crash services or execute arbitrary code on the system with elevated privileges.

Mitigation

Install update from vendor's website.

Vulnerable software versions

systemd: 244.2 - 244.3

External links

http://github.com/systemd/systemd/commit/ea0d0ede03c6f18dbc5036c5e9cccf97e415ccc2
http://github.com/systemd/systemd-stable/commit/e2d4cb9843c50eff76e9104fec6b448c0d7c8814

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.