Credentials management in Freedesktop systemd

1) Credentials management

EUVDB-ID: #VU35894

Risk: High

CVSSv4.0: 8.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2018-20839

CWE-ID: CWE-255 - Credentials Management

Exploit availability: No

Description

The vulnerability allows a remote non-authenticated attacker to execute arbitrary code.

systemd 242 changes the VT1 mode upon a logout, which allows attackers to read cleartext passwords in certain circumstances, such as watching a shutdown, or using Ctrl-Alt-F1 and Ctrl-Alt-F2. This occurs because the KDGKBMODE (aka current keyboard mode) check is mishandled.

Mitigation

Install update from vendor's website.

Vulnerable software versions

systemd: 242

CPE2.3

• cpe:2.3:a:freedesktop_org:systemd:242:*:*:*:*:*:*:*

External links

https://www.securityfocus.com/bid/108389
https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1803993
https://github.com/systemd/systemd/commit/9725f1a10f80f5e0ae7d9b60547458622aeb322f
https://github.com/systemd/systemd/pull/12378
https://security.netapp.com/advisory/ntap-20190530-0002/

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

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