Privilege escalation in Sudo

1) Stack-based buffer overflow

EUVDB-ID: #VU24810

Risk: Low

CVSSv3.1: 7.7 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-18634

CWE-ID: CWE-121 - Stack-based buffer overflow

Exploit availability: Yes

Description

The vulnerability allows a local user to execute arbitrary code on the target system.

The vulnerability exists due to a boundary error within the getln() function in tgetpass.c, if pwfeedback is enabled in /etc/sudoers. A local user can trigger stack-based buffer overflow and execute arbitrary code on the target system with elevated privileges.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Sudo: 1.8.0 - 1.8.30

External links

http://www.openwall.com/lists/oss-security/2020/01/30/6
http://www.openwall.com/lists/oss-security/2020/01/31/1
http://seclists.org/bugtraq/2020/Jan/44
http://support.apple.com/kb/HT210919
http://www.sudo.ws/alerts/pwfeedback.html
http://www.sudo.ws/security.html

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.