Penetration Testing mailing list archives
Re: DNS ACL ?
From: "Stephen J. Smoogen" <smooge () gmail com>
Date: Sat, 12 Nov 2005 11:23:23 -0700
On 11/11/05, John Hally <JHally () epnet com> wrote:
Hello All, I need a sanity check regarding DNS ACLs. For external facing DNS servers you need to allow only udp/53 inbound, correct? I know tcp/53 is used for zone transfers and requests/replies greater than a certain size, but they shouldn't typically happen for general dns queries correct?
I think that the backbone DNS servers and certain upstream DNS servers require TCP, and if for some reason a query can not fit into a single UDP packet it will switch to TCP. So if you do not have insane hostnames or extra info (long TXT sections etc), then TCP would not be needed to the world.. locking it down so that it only talks to known upstream boxes would probably be correct. -- Stephen J Smoogen. CSIRT/Linux System Administrator ------------------------------------------------------------------------------ Audit your website security with Acunetix Web Vulnerability Scanner: Hackers are concentrating their efforts on attacking applications on your website. Up to 75% of cyber attacks are launched on shopping carts, forms, login pages, dynamic content etc. Firewalls, SSL and locked-down servers are futile against web application hacking. Check your website for vulnerabilities to SQL injection, Cross site scripting and other web attacks before hackers do! Download Trial at: http://www.securityfocus.com/sponsor/pen-test_050831 -------------------------------------------------------------------------------
Current thread:
- DNS ACL ? John Hally (Nov 11)
- Re: DNS ACL ? Stephen J. Smoogen (Nov 13)
- RE: DNS ACL ? Jason Muskat (Nov 13)
- RE: DNS ACL ? Giancarlo Paolillo (Nov 13)
- Re: DNS ACL ? Thor (Hammer of God) (Nov 13)
- Re: DNS ACL ? Richard C Lewis (Nov 13)
- Re: DNS ACL ? Chris Brenton (Nov 13)
- Re: DNS ACL ? Lynx (Nov 13)
- Re: DNS ACL ? Justin Ferguson (Nov 14)
- <Possible follow-ups>
- Re: DNS ACL ? John Nemeth (Nov 13)
- RE: DNS ACL ? Maher Odeh (Nov 13)
- FW: DNS ACL ? Dario Ciccarone (dciccaro) (Nov 21)
(Thread continues...)