Re: ISC announces two BIND vulnerabilities

[Yves-Alexis Perez <corsac () debian org>]

On Fri, 2017-06-30 at 01:09 -0800, ISC Security Officer wrote:
> On Thursday (29 June) Internet Systems Consortium disclosed two security
> vulnerabilities in BIND.  Details on the individual vulnerabilities
> can be found in our knowledge base:
>
>   CVE-2017-3142:  https://kb.isc.org/article/AA-01504/74/CVE-2017-3142
>   CVE-2017-3143:  https://kb.isc.org/article/AA-01503/74/CVE-2017-3143
>
> New software releases have been issued containing these security fixes;
> they are available from our download page at http://www.isc.org/downloads
As per list policy, and since I'm following these for Debian, here's some more
details inline for the list.

The vulnerabilities are very similar to the knot one (no CVE yet) found by the
same researchers (Synaktiv):

CVE-2017-3142: An error in TSIG authentication can permit unauthorized zone
transfers

An attacker who is able to send and receive messages to an authoritative DNS
server and who has knowledge of a valid TSIG key name may be able to
circumvent TSIG authentication of AXFR requests via a carefully constructed
request packet. A server that relies solely on TSIG keys for protection with
no other ACL protection could be manipulated into:

* providing an AXFR of a zone to an unauthorized recipient
* accepting bogus NOTIFY packets

CVE-2017-3043: An error in TSIG authentication can permit unauthorized dynamic
updates

An attacker who is able to send and receive messages to an authoritative DNS
server and who has knowledge of a valid TSIG key name for the zone and service
being targeted may be able to manipulate BIND into accepting an unauthorized
dynamic update.

Regards,
-- 
Yves-Alexis

Attachment: signature.asc
Description: This is a digitally signed message part