Dnsmasq: Poisoning and Denial of Service vulnerabilities
Gentoo Linux Security Advisory
||GLSA 200504-03 / Dnsmasq
||April 04, 2005
||April 04, 2005: 01
All supported architectures
Dnsmasq is vulnerable to DNS cache poisoning attacks and a potential Denial
of Service from the local network.
Dnsmasq is a lightweight and easily-configurable DNS forwarder and
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.
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.
There is no known workaround at this time.
All Dnsmasq users should upgrade to the latest version:
Code Listing 3.1: Resolution
# emerge --sync
# emerge --ask --oneshot --verbose ">=net-dns/dnsmasq-2.22"