Privilege escalation in systemd

1) Input validation error

EUVDB-ID: #VU29539

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-2020-13776

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

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

The vulnerability exists due to systemd mishandles numerical usernames such as ones composed of decimal digits or 0x followed by hex digits, as demonstrated by use of root privileges when privileges of the 0x0 user account were intended.

Mitigation

Install update from vendor's website.

Vulnerable software versions

systemd: 1 - 245.6

CPE2.3

• cpe:2.3:a:freedesktop_org:systemd:245.6:*:*:*:*:*:*:*
• cpe:2.3:a:freedesktop_org:systemd:245.5:*:*:*:*:*:*:*
• cpe:2.3:a:freedesktop_org:systemd:245.4:*:*:*:*:*:*:*

External links

http://github.com/systemd/systemd/issues/15985
http://security.netapp.com/advisory/ntap-20200611-0003/

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.