[ GLSA 200904-10 ] Avahi: Denial of Service

[GLSA]

Gentoo Linux Security Advisory

Title: Avahi: Denial of Service (GLSA 200904-10)
Severity: normal
Exploitable: remote
Date: April 08, 2009
Bug(s): #260971
ID: 200904-10

Synopsis


An error in Avahi might lead to a Denial of Service via network and CPU
consumption.


Background


Avahi is a system that facilitates service discovery on a local
network.


Affected Packages

Package: net-dns/avahi
Vulnerable: < 0.6.24-r2
Unaffected: >= 0.6.24-r2
Architectures: All supported architectures


Description


Rob Leslie reported that the
originates_from_local_legacy_unicast_socket() function in
avahi-core/server.c does not account for the network byte order of a
port number when processing incoming multicast packets, leading to a
multicast packet storm.


Impact


A remote attacker could send specially crafted legacy unicast mDNS
query packets to the Avahi daemon, resulting in a Denial of Service due
to network bandwidth and CPU consumption.


Workaround


There is no known workaround at this time.


Resolution


All Avahi users should upgrade to the latest version: