GLSA 200504-03: Dnsmasq: Poisoning and Denial of Service vulnerabilities

http://security.gentoo.org/

Severity:	low
Title:	Dnsmasq: Poisoning and Denial of Service vulnerabilities
Date:	04/04/2005
Bugs:	#86718
ID:	200504-03

Synopsis

Dnsmasq is vulnerable to DNS cache poisoning attacks and a potential Denial of Service from the local network.

Background

Dnsmasq is a lightweight and easily-configurable DNS forwarder and DHCP server.

Affected packages

Package	Vulnerable	Unaffected	Architecture(s)
net-dns/dnsmasq	< 2.22	>= 2.22	All supported architectures

Description

Dnsmasq does not properly detect that DNS replies received do not correspond to any DNS query that was sent. Rob Holland of the Gentoo Linux Security Audit team also discovered two off-by-one buffer overflows that could crash DHCP lease files parsing.

Impact

A remote attacker could send malicious answers to insert arbitrary DNS data into the Dnsmasq cache. These attacks would in turn help an attacker to perform man-in-the-middle and site impersonation attacks. The buffer overflows might allow an attacker on the local network to crash Dnsmasq upon restart.

Workaround

There is no known workaround at this time.

Resolution

All Dnsmasq users should upgrade to the latest version:

    # emerge --sync
    # emerge --ask --oneshot --verbose ">=net-dns/dnsmasq-2.22"

References

Dnsmasq Changelog

Availability

This GLSA and any updates to it are available for viewing at the Gentoo Security Website: http://security.gentoo.org/glsa/glsa-200504-03.xml

Concerns?

Security is a primary focus of Gentoo Linux and ensuring the confidentiality and security of our users machines is of utmost importance to us. Any security concerns should be addressed to security@gentoo.org or alternatively, you may file a bug at https://bugs.gentoo.org.