Avahi: "netlink" message vulnerability

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Updated November 20, 2006

1.  Gentoo Linux Security Advisory

Version Information

Advisory Reference GLSA 200611-13 / avahi
Release Date November 20, 2006
Latest Revision November 20, 2006: 01
Impact normal
Exploitable local
Package Vulnerable versions Unaffected versions Architecture(s)
net-dns/avahi < 0.6.15 >= 0.6.15 All supported architectures

Related bugreports: #154322

Synopsis

Avahi fails to verify the origin of netlink messages, which could allow local users to spoof network changes.

2.  Impact Information

Background

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

Description

Avahi does not check that the netlink messages come from the kernel instead of a user-space process.

Impact

A local attacker could exploit this vulnerability by crafting malicious netlink messages and trick Avahi to react to fake network changes. This could lead users to connect to untrusted services without knowing.

3.  Resolution Information

Workaround

There is no known workaround at this time.

Resolution

All Avahi users should upgrade to the latest version:

Code Listing 3.1: Resolution

# emerge --sync
# emerge --ask --oneshot --verbose ">=net-dns/avahi-0.6.15"

4.  References