oss-sec mailing list archives

Re: CVE Request: glibc getaddrinfo() stack overflow


From: Florian Weimer <fweimer () redhat com>
Date: Wed, 03 Apr 2013 17:07:58 +0200

On 04/03/2013 04:55 PM, Sebastian Krahmer wrote:

glibc resolver surprisingly seems to accept indeed larger
UDP packets than DNS servers would send without EDNS0.
But depending on setup its probably hard to get such large
packets through your local recursive DNS, not to speak
about the firewall. Maybe its possible to signal truncation
and force a TCP connect?

Yes, this is with the TCP transport. With a suitably prepared zone, I can get up to

$ getent hosts  ... | wc -l
4093

A records (over DNS, just to be clear).

--
Florian Weimer / Red Hat Product Security Team


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