Multiple DNS implementations vulnerable to cache poisoning
eric at mail.rockefeller.edu
Wed Jul 9 15:24:54 CDT 2008
Anyone using Infoblox DNSOne? They claimed to have fixed their BIND version
but I still see issues with source ports staying the same.
Sr. Network Technician
Rockefeller University IT Dept.
From: Patrick W. Gilmore [mailto:patrick at ianai.net]
Sent: Wednesday, July 09, 2008 4:15 PM
To: nanog at merit.edu
Subject: Re: Multiple DNS implementations vulnerable to cache poisoning
On Jul 9, 2008, at 4:07 PM, Fernando Gont wrote:
> At 12:41 p.m. 09/07/2008, Steven M. Bellovin wrote:
>> It's worth noting that the basic idea of the attack isn't new. Paul
>> Vixie described it in 1995 at the Usenix Security Conference
>> -- in a section titled "What We Cannot Fix", he wrote:
>> With only 16 bits worth of query ID and 16 bits worth of UDP
>> port number, it's hard not to be predictable. A determined
>> attacker can try all the numbers in a very short time and can
>> use patterns derived from examination of the freely available
>> BIND code. Even if we had a white noise generator to help
>> randomize our numbers, it's just too easy to try them all.
> We have one IETF ID on port randomization for years:
> While this does not make the attack impossible, it does make it much
> The same thing applies to those RST attacks circa 2004.
> Most of these blind attacks assume the source port numbers are easy
> to guess. But... why should they?
Because many name servers use one port, or easily guessable sequence
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