#VU79113 Infinite loop in Avahi - CVE-2021-3468

Vulnerability identifier: #VU79113

Vulnerability risk: Low

CVSSv4.0: 4.3 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2021-3468

CWE-ID: CWE-835

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Avahi
Universal components / Libraries / Libraries used by multiple products

Vendor: avahi.org

Description

The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to event used to signal the termination of the client connection on the avahi Unix socket is not correctly handled in the client_work() function. A local user can consume all available system resources and cause denial of service conditions.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Avahi: 0.6.1 - 0.8

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External links
https://bugzilla.redhat.com/show_bug.cgi?id=1939614
https://lists.debian.org/debian-lts-announce/2022/06/msg00009.html
https://lists.debian.org/debian-lts-announce/2023/06/msg00028.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.