bind9 - cache poisoning

Several cache-poisoning vulnerabilities have been discovered in BIND.
These vulnerabilities apply only if DNSSEC validation is enabled and
trust anchors have been installed, which is not the default.

The Common Vulnerabilities and Exposures project identifies the
following problems:

• CVE-2010-0097
  BIND does not properly validate DNSSEC NSEC records, which allows
  remote attackers to add the Authenticated Data (AD) flag to a forged
  NXDOMAIN response for an existing domain.
• CVE-2010-0290
  When processing crafted responses containing CNAME or DNAME records,
  BIND is subject to a DNS cache poisoning vulnerability, provided that
  DNSSEC validation is enabled and trust anchors have been installed.
• CVE-2010-0382
  When processing certain responses containing out-of-bailiwick data,
  BIND is subject to a DNS cache poisoning vulnerability, provided that
  DNSSEC validation is enabled and trust anchors have been installed.

In addition, this update introduce a more conservative query behavior
in the presence of repeated DNSSEC validation failures, addressing the
“roll over and die” phenomenon. The new version also supports the
cryptographic algorithm used by the upcoming signed ICANN DNS root
(RSASHA256 from RFC 5702), and the NSEC3 secure denial of existence
algorithm used by some signed top-level domains.

This update is based on a new upstream version of BIND 9, 9.6-ESV-R1.
Because of the scope of changes, extra care is recommended when
installing the update. Due to ABI changes, new Debian packages are
included, and the update has to be installed using “apt-get
dist-upgrade” (or an equivalent aptitude command).

For the stable distribution (lenny), these problems have been fixed in
version 1:9.6.ESV.R1+dfsg-0+lenny1.

For the unstable distribution (sid), these problems have been fixed in
version 1:9.7.0.dfsg-1.

We recommend that you upgrade your bind9 packages.