Three publicly available DNS exploits are available that exploit the recent DNS vulnerabilities brought to light by Dan Kaminsky.  These exploits have been downloaded over 15,000 times, although we have no idea how many of these downloads are being used maliciously.

Multiple major ISP still have not patched and remain vulnerable.   Even if your organization patches for this vulnerability, you business may still be at risk if your upstream provider has not.  If you have not checked your exposure from your organization and your service provide, I highly suggest you doing this now.

Tags: DNS Cache Poisoning, Exploits, In the wild, Vulnerablities

Author: Christopher

There are currently known vulnerabilities with DNS servers across all implementations.  These vulnerabilities are not vendor specific, in fact all DNS distributions are vulnerable.  I recommend all organizations develop an action plan immediately to identify and patch all DNS servers, applications, and clients on all networks in your control.

These vulnerabilities expose vulnerable DNS servers to DNS cache poisoning, this potentially can effect proper email delivery and what website you actually visit when entering a URL into a browser.

DNS specifically calls for 16 bit transaction ID field, which would require 32,768 “guesses” to predict the ID.  Many implementations use a smaller number of bits, and thus would require considerably fewer guesses.

US-CERT has an excellent write up on this vulnerability here.

You can find patch specifics for Microsoft here.

If you are running BIND 8, there is currently no solution and no plans to fix this problem for this platform, it is highly recommended to immediately look at upgrading to BIND 9.

If you only apply one patch in 2008, this should be it!

If you are using DNS from your ISP, you may still be vulnerable!

To assist organizations in containing this issue, I put together a few actions steps to get everyone on track.

1. Identify all DNS servers on your network and any networks you are responsible for.  To be sure, you may want to run a port scan for anything listening on UDP port 53.
2. Identify vendors responsible for each and every DNS server found from step 1.
3. Refer to US-Cert for links to each vendor to the appropriate patch documentation.
4. Patch all Servers.
5. Repeat for all DNS Clients, although these patches are more focused on DNS Servers.

It is highly recommended all servers be patched before the Black Hat convention on August 6th when more information will be disclosed.

UPDATE:

You can check your upstream DNS Servers here:
http://www.doxpara.com/

Tags: BIND, DNS, DNS Cache Poisoning, US-CERT, VU#800113, Vulnerabilities, Vulnerability

Author: Christopher