Subject: [ASA-201611-3] bind: denial of service

Arch Linux Security Advisory ASA-201611-3
=========================================

Severity: High
Date    : 2016-11-01
CVE-ID  : CVE-2016-8864
Package : bind
Type    : denial of service
Remote  : Yes
Link    : https://security.archlinux.org/AVG-59

Summary
=======

The package bind before version 9.11.0.P1-1 is vulnerable to denial of
service.

Resolution
==========

Upgrade to 9.11.0.P1-1.

# pacman -Syu "bind>=9.11.0.P1-1"

The problem has been fixed upstream in version 9.11.0.P1.

Workaround
==========

None.

Description
===========

A defect in BIND's handling of responses containing a DNAME answer can
cause a resolver to exit after encountering an assertion failure in
db.c or resolver.c

During processing of a recursive response that contains a DNAME record
in the answer section, BIND can stop execution after encountering an
assertion error in resolver.c (error message: "INSIST((valoptions &
0x0002U) != 0) failed") or db.c (error message: "REQUIRE(targetp !=
((void *)0) && *targetp == ((void *)0)) failed").

A server encountering either of these error conditions will stop,
resulting in denial of service to clients.  The risk to authoritative
servers is minimal; recursive servers are chiefly at risk.

Impact
======

An attacker can send a crafted DNAME answer to crash the application.

References
==========

https://kb.isc.org/article/AA-01434/0
http://ftp.isc.org/isc/bind9/9.11.0-P1/RELEASE-NOTES-bind-9.11.0-P1.html
https://security.archlinux.org/CVE-2016-8864