CVE-2019-6468: BIND Supported Preview Edition can exit with an assertion failure if nxdomain-redirect is used

Michael McNally <[email protected]> Wed, 24 Apr 2019 17:21:42 -0800
Newsgroups	gmane.network.dns.bind.announce
Message-ID	<[email protected]>
CVE:                 CVE-2019-6468
Document version:    2.0
Posting date:        24 April 2019
Program impacted:    BIND
Versions affected:   BIND Supported Preview Edition version
                     9.10.5-S1 -> 9.11.5-S5. ONLY BIND Supported
                     Preview Edition releases are affected.
Severity:            Medium
Exploitable:         Remotely

Description:

   In BIND Supported Preview Edition, an error in the nxdomain-redirect
   feature can occur in versions which support EDNS Client Subnet
   (ECS) features. In those versions which have ECS support, enabling
   nxdomain-redirect is likely to lead to BIND exiting due to
   assertion failure.

Impact:

   If nxdomain-redirect is enabled (via configuration) in a vulnerable
   BIND release, a malicious party can cause BIND to exit by
   deliberately triggering the bug.

CVSS Score:          5.9
CVSS Vector:         CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

For more information on the Common Vulnerability Scoring System and
to obtain your specific environmental score please visit:
https://www.first.org/cvss/calculator/3.0#CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H.

Workarounds:

   Exploitation of this defect can be effectively prevented by
   disabling the nxdomain-redirect feature in the nameserver's
   configuration.

Active exploits:

   None known.

Solution:

   Upgrade to the patched release most closely related to your
   current version of BIND:

   BIND Supported Preview Edition is a special feature preview
   branch of BIND provided to eligible ISC support customers.

   -  BIND 9.11.5-S6
   -  BIND 9.11.6-S1

Document revision history:

   1.0 Early Notification, 15 April 2019
   1.1 Added reference to BIND 9.11.6-S1 in Solution section
   2.0 Public Disclosure, 24 April 2019

Related documents:

See our BIND 9 Security Vulnerability Matrix for a complete listing
of security vulnerabilities and versions affected.

Do you still have questions? Questions regarding this advisory
should go to [email protected]. To report a new issue, please
encrypt your message using [email protected]'s PGP key which
can be found here:
   https://www.isc.org/downloads/software-support-policy/openpgp-key
If you are unable to use encrypted email, you may also report new
issues at: https://www.isc.org/community/report-bug/.

Note:

   ISC patches only currently supported versions. When possible we
   indicate EOL versions affected. (For current information on which
   versions are actively supported, please see
   https://www.isc.org/downloads/.)

ISC Security Vulnerability Disclosure Policy:

   Details of our current security advisory policy and practice can
   be found in the ISC Software Defect and Security Vulnerability
   Disclosure Policy.

Legal Disclaimer:

   Internet Systems Consortium (ISC) is providing this notice on
   an "AS IS" basis. No warranty or guarantee of any kind is expressed
   in this notice and none should be implied. ISC expressly excludes
   and disclaims any warranties regarding this notice or materials
   referred to in this notice, including, without limitation, any
   implied warranty of merchantability, fitness for a particular
   purpose, absence of hidden defects, or of non-infringement. Your
   use or reliance on this notice or materials referred to in this
   notice is at your own risk. ISC may change this notice at any
   time. A stand-alone copy or paraphrase of the text of this
   document that omits the document URL is an uncontrolled copy.
   Uncontrolled copies may lack important information, be out of
   date, or contain factual errors.

_______________________________________________
bind-announce mailing list
[email protected]
https://lists.isc.org/mailman/listinfo/bind-announce
pEpkey.asc (application/pgp-keys, 12.8 KB)