#VU50040 Heap-based buffer overflow in Sudo - CVE-2021-3156

Vulnerability identifier: #VU50040

Vulnerability risk: Low

CVSSv4.0: 8.5 [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:A/U:Clear]

CVE-ID: CVE-2021-3156

CWE-ID: CWE-122

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 escalate privileges on the system.

The vulnerability exists due to a boundary error in sudo. A local user can pass specially crafted data to the application, trigger heap-based buffer overflow and execute arbitrary code on the target system with root privileges.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Sudo: 1.8.0 - 1.9.5p1

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External links
https://www.qualys.com/2021/01/26/cve-2021-3156/baron-samedit-heap-based-overflow-sudo.txt
https://bugzilla.redhat.com/show_bug.cgi?id=1917684
https://access.redhat.com/security/cve/CVE-2021-3156
https://www.sudo.ws/alerts/unescape_overflow.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?

Yes. This vulnerability is being exploited in the wild.