CVE-2021-3502

Publication date 7 May 2021

Last updated 25 August 2025

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

5.5 · Medium

Score breakdown

Description

A flaw was found in avahi 0.8-5. A reachable assertion is present in avahi_s_host_name_resolver_start function allowing a local attacker to crash the avahi service by requesting hostname resolutions through the avahi socket or dbus methods for invalid hostnames. The highest threat from this vulnerability is to the service availability.

Read the notes from the security team

Status

Package Ubuntu Release Status
avahi 22.04 LTS jammy
Fixed 0.8-5ubuntu4
21.10 impish
Fixed 0.8-5ubuntu4
21.04 hirsute
Fixed 0.8-5ubuntu3.1
20.10 groovy
Fixed 0.8-3ubuntu1.1
20.04 LTS focal
Not affected
18.04 LTS bionic
Not affected
16.04 LTS xenial
Not affected
14.04 LTS trusty
Not affected

Notes

mdeslaur

introduced in 0.8

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package Patch details
avahi

Severity score breakdown

CVSS version: CVSS v3.0

Base score 5.5 · Medium

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

References

Related Ubuntu Security Notices (USN)

Other references

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