Debian Security Advisory

DSA-1619-1 python-dns -- DNS response spoofing

Date Reported:
27 Jul 2008
Affected Packages:
Security database references:
In the Debian bugtracking system: Bug 490217.
In Mitre's CVE dictionary: CVE-2008-1447, CVE-2008-4099.
More information:

Multiple weaknesses have been identified in PyDNS, a DNS client implementation for the Python language. Dan Kaminsky identified a practical vector of DNS response spoofing and cache poisoning, exploiting the limited entropy in a DNS transaction ID and lack of UDP source port randomization in many DNS implementations. Scott Kitterman noted that python-dns is vulnerable to this predictability, as it randomizes neither its transaction ID nor its source port. Taken together, this lack of entropy leaves applications using python-dns to perform DNS queries highly susceptible to response forgery.

The Common Vulnerabilities and Exposures project identifies this class of weakness as CVE-2008-1447 and this specific instance in PyDNS as CVE-2008-4099.

For the stable distribution (etch), these problems have been fixed in version 2.3.0-5.2+etch1.

We recommend that you upgrade your python-dns package.

Fixed in:

Debian GNU/Linux 4.0 (etch)

Architecture-independent component:

MD5 checksums of the listed files are available in the original advisory.