CVE-2016-1285: An error parsing input received by the rndc control channel can cause an assertion failure in sexpr.c or alist.c
mcnally at isc.org
Wed Mar 9 21:05:20 UTC 2016
Document Version: 2.0
Posting date: 09 March 2016
Program Impacted: BIND
Versions affected: 9.2.0 -> 9.8.8, 9.9.0 -> 9.9.8-P3,
9.9.3-S1 -> 9.9.8-S5, 9.10.0 -> 9.10.3-P3
Exploitable: Remotely (on systems which accept control
channel input from remote addresses.)
Testing by ISC has uncovered a defect in control channel input
handling which can cause named to exit due to an assertion failure
in sexpr.c or alist.c when a malformed packet is sent to named's
control channel (the interface which allows named to be controlled
using the 'rndc" server control utility).
This assertion occurs before authentication but after
network-address-based access controls have been applied. Or in
other words: an attacker does not need to have a key or other
authentication, but does need to be within the address list
specified in the "controls" statement in named.conf which enables
the control channel. If no "controls" statement is present in
named.conf, named still defaults to listening for control channel
information on loopback addresses (127.0.0.1 and ::1) if the
file rndc.key is present in the configuration directory and
contains a valid key.
A search for similar problems revealed an associated defect in
the rndc server control utility whereby a malformed response
from the server could cause the rndc program to crash. For
completeness, it is being fixed at the same time even though
this defect in the rndc utility is not in itself exploitable.
All servers are vulnerable if they accept remote commands on the
control channel. Servers which are vulnerable can be stopped
by an attacker sending the offending packet if the attacker is
sending from a system listed within the address list specified
in the "controls" statement (or from localhost if the control
channel is using the default address list) resulting in denial
of service to clients.
CVSS Score: 7.8
CVSS Vector: (AV:N/AC:L/Au:N/C:N/I:N/A:C)
For more information on the Common Vulnerability Scoring System and
to obtain your specific environmental score please visit:
Restrict access to the control channel (by using the "controls"
configuration statement in named.conf) to allow connection only
from trusted systems.
Note that if no "controls" statement is present, named defaults
to allowing control channel connections only from localhost
(127.0.0.1 and ::1) if and only if the file rndc.key exists in
the configuration directory and contains valid key syntax. If
rndc.key is not present and no "controls" statement is present
in named.conf, named will not accept commands on the control
No known active exploits.
Upgrade to the patched release most closely related to your
current version of BIND.
+ BIND 9 version 9.9.8-P4
+ BIND 9 version 9.10.3-P4
BIND 9 Supported Preview edition is a feature preview version of
BIND provided exclusively to eligible ISC Support customers.
+ BIND 9 Supported Preview Edition version 9.9.8-S6
Document Revision History:
1.0 Advance Notification 09 March 2016
1.1 "Versions affected" and "Solution" text expanded to cover BIND 9
Supported Preview Edition, 03 March 2016
2.0 Public Disclosure. 09 March 2016
See our BIND9 Security Vulnerability Matrix at
https://kb.isc.org/article/AA-00913 for a complete listing of
Security Vulnerabilities and versions affected.
If you'd like more information on ISC Subscription Support and
Advance Security Notifications, please visit http://www.isc.org/support/.
Do you still have questions? Questions regarding this advisory
should go to security-officer at isc.org. To report a new issue,
please encrypt your message using security-officer at isc.org's PGP
key which can be found here:
If you are unable to use encrypted email, you may also report new
issues at: https://www.isc.org/community/report-bug/.
ISC patches only currently supported versions. When possible we
indicate EOL versions affected. (For current information on
which versions are actively supported, please see
ISC Security Vulnerability Disclosure Policy:
Details of our current security advisory policy and practice can
be found here:
This Knowledge Base article https://kb.isc.org/article/AA-01352 is
the complete and official security advisory document.
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.
(c) 2001-2016 Internet Systems Consortium
More information about the bind-announce