#VU24810 Stack-based buffer overflow in Sudo - CVE-2019-18634

Vulnerability identifier: #VU24810

Vulnerability risk: Low

CVSSv4.0: 7.1 [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/E:P/U:Clear]

CVE-ID: CVE-2019-18634

CWE-ID: CWE-121

Exploitation vector: Local

Exploit availability: Yes

Vulnerable software:
Sudo
Client/Desktop applications / Software for system administration

Vendor: Sudo

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

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

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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. However, proof of concept for this vulnerability is available.