#VU49883 Link following in Sudo - CVE-2021-23239

Vulnerability identifier: #VU49883

Vulnerability risk: Low

CVSSv4.0: 0.4 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-23239

CWE-ID: CWE-59

Exploitation vector: Local

Exploit availability: No

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

Vendor: Sudo

Description

The vulnerability allows a local authenticated user to gain access to sensitive information.

The sudoedit personality of Sudo before 1.9.5 may allow a local unprivileged user to perform arbitrary directory-existence tests by winning a sudo_edit.c race condition in replacing a user-controlled directory by a symlink to an arbitrary path.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Sudo: 1.9.0 - 1.9.4p2

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External links
https://bugzilla.suse.com/show_bug.cgi?id=CVE-2021-23239
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/EE42Y35SMJOLONAIBNYNFC7J44UUZ2Y6/
https://www.sudo.ws/stable.html#1.9.5

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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.