Full Disclosure mailing list archives
Re: Linux: telnet/ssh and other clients can connect to wrong host in case of mixed IPv4/IPv6 environment and search suffices are used in /etc/resolv.conf
From: Juri Haberland <list-security.full-disclosure () koschikode com>
Date: Sun, 23 Jul 2006 00:50:13 +0000 (UTC)
Peter Bieringer <pb () bieringer de> wrote:
During digging behind strange DNS requests receiving my DNS server I found, that there must be something broken in resolver/client address handling.
[snip]
BTW: there is another issue that too much lookups are done, see the current query sequence here: AAAA? test.unknown. (30) AAAA? test.unknown.1.getaddrinfo.bieringer.de. (57) AAAA? test.unknown.2.getaddrinfo.bieringer.de. (57) [successful AAAA] A? test.unknown. (30) A? test.unknown.1.getaddrinfo.bieringer.de. (57) A? test.unknown.2.getaddrinfo.bieringer.de. (57) A? test.unknown.3.getaddrinfo.bieringer.de. (57) [successful A] I would expect a different order at all but I think this is a related problem. AAAA? test.unknown. (30) A? test.unknown. (30) AAAA? test.unknown.1.getaddrinfo.bieringer.de. (57) A? test.unknown.1.getaddrinfo.bieringer.de. (57) AAAA? test.unknown.2.getaddrinfo.bieringer.de. (57) [successful AAAA] A? test.unknown.2.getaddrinfo.bieringer.de. (57) A? test.unknown.3.getaddrinfo.bieringer.de. (57) [successful A, but different name than successful AAAA, skipped!]
I would assume the following rules: as IPv6 is superior to IPv4 I would try all IPv6 addresses before falling back to IPv4. Think of NFSv3 vs. NFSv2... Cheers, Juri _______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.grok.org.uk/full-disclosure-charter.html Hosted and sponsored by Secunia - http://secunia.com/
Current thread:
- Linux: telnet/ssh and other clients can connect to wrong host in case of mixed IPv4/IPv6 environment and search suffices are used in /etc/resolv.conf Peter Bieringer (Jul 22)
- Re: Linux: telnet/ssh and other clients can connect to wrong host in case of mixed IPv4/IPv6 environment and search suffices are used in /etc/resolv.conf Juri Haberland (Jul 22)
- Re: Linux: telnet/ssh and other clients can connect to wrong host in case of mixed IPv4/IPv6 environment and search suffices are used in /etc/resolv.conf Valdis . Kletnieks (Jul 22)