Re: [9fans] dns exploits (self-promotion remix)

2008-07-28 Thread Wes Kussmaul
erik quanstrom wrote: what is this "web 2.0" of which you speak? Web 2.0, n. A space created by artists who got all excited when they heard the word "sandbox," not realizing it meant the opposite of what they thought. wk

Re: [9fans] dns exploits (self-promotion remix)

2008-07-27 Thread erik quanstrom
> > 2. who does recursive queries on external interfaces? > > i would have considerd this a configuration error and > > security problem ten years ago. > > > > Tell that to the rest of the internet. without reasonable configuration, most any machine can be made trivially vulnerable. > vectors

Re: [9fans] dns exploits (self-promotion remix)

2008-07-27 Thread don bailey
i don't understand this 1. plan 9 never used a static source port for queries, and more importantly Erm, sequential source ports are close enough. 2. who does recursive queries on external interfaces? i would have considerd this a configuration error and security problem ten years ago. T

Re: [9fans] dns exploits (self-promotion remix)

2008-07-27 Thread a
// 1. plan 9 never used a static source port for queries, Using dynamic ports is better than static, but if they're sequential (or otherwise predictable), it doesn't buy you all that much. // 2. who does recursive queries on external interfaces? I've been traveling in companies and countries w

Re: [9fans] dns exploits (self-promotion remix)

2008-07-27 Thread erik quanstrom
> The exploit doesn't simply rely on the 16bit dns XID. > Rather, it's reliant on the fact that bind servers > (and some others) send requests from a static port. > Obviously, if you control a DNS server or you can > sniff the target DNS server's path, you can figure > this out. > > The second par

Re: [9fans] dns exploits (self-promotion remix)

2008-07-27 Thread don bailey
if you're running ndb/dns -r, you need to build and boot a new kernel to get the full 30 bits. Bing!

Re: [9fans] dns exploits (self-promotion remix)

2008-07-27 Thread don bailey
The exploit doesn't simply rely on the 16bit dns XID. Rather, it's reliant on the fact that bind servers (and some others) send requests from a static port. Obviously, if you control a DNS server or you can sniff the target DNS server's path, you can figure this out. The second part to the trick

Re: [9fans] dns exploits (self-promotion remix)

2008-07-27 Thread Russ Cox
>> those things combined mean that you get 15 bits of randomness >> from query id and 15 from source port, giving 30 bits, >> so ndb/dns is okay (for now). > > why only 15 in the query id? that's an artifact of rand() > which returns 0 ≤ n ≤ 0x7fff. why not return numbers > between 0 and 0x?

Re: [9fans] dns exploits (self-promotion remix)

2008-07-27 Thread erik quanstrom
> those things combined mean that you get 15 bits of randomness > from query id and 15 from source port, giving 30 bits, > so ndb/dns is okay (for now). why only 15 in the query id? that's an artifact of rand() which returns 0 ≤ n ≤ 0x7fff. why not return numbers between 0 and 0x? - erik

Re: [9fans] dns exploits (self-promotion remix)

2008-07-27 Thread Russ Cox
>> i'm not a dns user (just the client side) on Plan9, >> is the server part vulnerable to the recent poisonning attacks? > > i think the recent dns cache-poisoning vulnerability > is more self promotion than substance. i agreed until i saw the supposed exploit details that were published last