CVE-2017-6519

Publication date 30 April 2017

Last updated 25 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

avahi-daemon in Avahi through 0.6.32 and 0.7 inadvertently responds to IPv6 unicast queries with source addresses that are not on-link, which allows remote attackers to cause a denial of service (traffic amplification) and may cause information leakage by obtaining potentially sensitive information from the responding device via port-5353 UDP packets. NOTE: this may overlap CVE-2015-2809.

Mitigation

Block udp port 5353 at perimeter firewall

Status

Show unmaintained releases

Package	Ubuntu Release	Status
avahi	18.10 cosmic	Fixed 0.7-4ubuntu2.1
	18.04 LTS bionic	Fixed 0.7-3.1ubuntu1.2
	17.10 artful	Ignored end of life
	17.04 zesty	Ignored end of life
	16.10 yakkety	Ignored end of life
	16.04 LTS xenial	Fixed 0.6.32~rc+dfsg-1ubuntu2.3
	14.04 LTS trusty	Fixed 0.6.31-4ubuntu1.3
	12.04 LTS precise	Ignored end of life

Patch details

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

Package	Patch details
avahi	Upstream: e111def

Severity score breakdown

Parameter	Value
Base score	9.1 · Critical
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality	High
Integrity impact	None
Availability impact	High
Vector	CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H