[ GLSA 200801-16 ] MaraDNS: CNAME Denial of Service

[GLSA]

Gentoo Linux Security Advisory

Title: MaraDNS: CNAME Denial of Service (GLSA 200801-16)
Severity: normal
Exploitable: remote
Date: January 29, 2008
Bug(s): #204351
ID: 200801-16

Synopsis

MaraDNS is prone to a Denial of Service vulnerability impacting CNAME resolution.

Background

MaraDNS is a package that implements the Domain Name Service (DNS) with resolver and caching ability.

Affected Packages

Package: net-dns/maradns
Vulnerable: < 1.2.12.08
Unaffected: >= 1.2.12.08
Architectures: All supported architectures


Description

Michael Krieger reported that a specially crafted DNS could prevent an authoritative canonical name (CNAME) record from being resolved because of an "improper rotation of resource records".

Impact

A remote attacker could send specially crafted DNS packets to a vulnerable server, making it unable to resolve CNAME records.

Workaround

Add "max_ar_chain = 2" to the "marac" configuration file.

Resolution

All MaraDNS users should upgrade to the latest version: