#VU60742 UNIX hardlink following in Snapd - CVE-2021-44730

Vulnerability identifier: #VU60742

Vulnerability risk: Low

CVSSv4.0: 5.9 [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:U/U:Clear]

CVE-ID: CVE-2021-44730

CWE-ID: CWE-62

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Snapd
Universal components / Libraries / Software for developers

Vendor: snapcore

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a hardlink following issue within the the snap-confine binary. A local user can create a hardlink to system binaries and execute them with elevated privileges.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Snapd: 2.0 - 2.54.2

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External links
https://github.com/snapcore/snapd/releases/tag/2.54.3

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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.