ESB-2018.1756.2 - UPDATE [Win][UNIX/Linux] BIND: Multiple vulnerabilities 2018-07-11

Printable version
PGP/GPG verifiable version

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256

===========================================================================
             AUSCERT External Security Bulletin Redistribution

                              ESB-2018.1756.2
        Some versions of BIND can improperly permit recursive query
                      service to unauthorized clients
                               11 July 2018

===========================================================================

        AusCERT Security Bulletin Summary
        ---------------------------------

Product:           BIND
Publisher:         ISC
Operating System:  UNIX variants (UNIX, Linux, OSX)
                   Windows
Impact/Access:     Denial of Service        -- Remote/Unauthenticated
                   Access Confidential Data -- Remote/Unauthenticated
Resolution:        Patch/Upgrade
CVE Names:         CVE-2018-5738  

Original Bulletin: 
   https://kb.isc.org/article/AA-01616/0/
   https://kb.isc.org/article/AA-01632/81/BIND-9.9.13-Release-Notes.html
   https://kb.isc.org/article/AA-01633/81/BIND-9.10.8-Release-Notes.html
   https://kb.isc.org/article/AA-01634/81/BIND-9.11.4-Release-Notes.html
   https://kb.isc.org/article/AA-01635/81/BIND-9.12.2-Release-Notes.html

Comment: This bulletin contains five (5) ISC security advisories.

Revision History:  July 11 2018: Patched in maintenance releases 9.9.13, 9.10.8, 9.11.4 and 9.12.2.
                   June 13 2018: Initial Release

- --------------------------BEGIN INCLUDED TEXT--------------------

Please note that for this vulnerability ISC is not issuing replacement
software releases.  Safe, effective, and side-effect-free configuration
workarounds are available for those whose configurations are affected.
The vulnerability will be fixed in upcoming maintenance releases so that
it cannot recur, but until maintenance releases containing the fix are
released we recommend use of any of the options listed in the workarounds
section.

If using the configuration workarounds is impractical for you, you may
request a patch diff containing an advance version of the fix by sending
e-mail to security-officer at isc.org

- -----


CVE:                 CVE-2018-5738
Document Version:    2.0
Posting date:        12 June 2018
Program Impacted:    BIND
Versions affected:   9.9.12, 9.10.7, 9.11.3, 9.12.0->9.12.1-P2,
                     the development release 9.13.0, and also
                     releases 9.9.12-S1, 9.10.7-S1, 9.11.3-S1,
                     and 9.11.3-S2 from BIND 9 Supported Preview Edition.
Severity:            Medium
Exploitable:         Remotely

Description:

   Change #4777 (introduced in October 2017) introduced an unforeseen
   issue in releases which were issued after that date, affecting
   which clients are permitted to make recursive queries to a BIND
   nameserver.

   The intended (and documented) behavior is that if an operator
   has not specified a value for the "allow-recursion" setting, it
   SHOULD default to one of the following:

   +  none, if "recursion no;" is set in named.conf, or

   +  a value inherited from the "allow-query-cache" or "allow-query"
      settings IF "recursion yes;" (the default for that setting) AND
      match lists are explicitly set for "allow-query-cache" or
"allow-query"
      (see the BIND9 Administrative Reference Manual section 6.2 for more
      details), or

   +  the intended default of "allow-recursion {localhost; localnets;};"
      if "recursion yes;" is in effect and no values are explicitly set
      for "allow-query-cache" or "allow-query".

   However, because of the regression introduced by change #4777,
   it is possible when "recursion yes;" is in effect and no match
   list values are provided for "allow-query-cache" or "allow-query"
   for the setting of "allow-recursion" to inherit a setting of all
   hosts from the "allow-query" setting default, improperly permitting
   recursion to all clients.

Impact:

   There are several potential problems which can be caused by
   improperly permitting recursive service to unauthorized clients,
   including:

   +  Additional queries from unauthorized clients may increase the
      load on a server, possibly degrading service to authorized clients.

   +  Allowing queries from unauthorized clients can potentially allow
      a server to be co-opted for use in DNS reflection attacks.

   +  An attacker may be able to deduce which queries a server has
      previously serviced by examining the results of queries answered
      from the cache, potentially leaking private information about what
      queries have been performed.

CVSS Score:          5.3
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:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Workarounds:

   A number of configuration workarounds are available which
   completely avoid the problem.

   If an operator has not chosen to specify some other permission,
   explicitly specifying "allow-query {localnets; localhost;};" in
   named.conf will provide behavior equivalent to the intended
   default.

   If the default setting is not appropriate (because the operator
   wants a different behavior) then depending on which clients are
   intended to be able to receive service for recursive queries,
   explicitly setting a match list value for any of:

   +  allow-recursion
   +  allow-query
   +  allow-query-cache

   will prevent the "allow-recursion" control from improperly
   inheriting a setting from the allow-query default.  If a value
   is set for any of those values the behavior of allow-recursion
   will be set directly or inherited from one of the other values
   as described in the BIND Adminstrator Reference Manual section 6.2

   Servers which are not intended to perform recursion at all may
   also effectively prevent this condition by setting "recursion no;"
   in named.conf

Active exploits:

   We are not aware of any exploits deliberately targeting this
   specific defect but it is not uncommon for scanners to search
   for open resolvers for use in reflection attacks and other
   mischief.  We have at least one report from an operator who
   discovered that unauthorized clients were successfully making
   queries to his server and it is reasonable to assume that other
   servers with similar configurations may be currently affected
   although their operators are unaware.

Solution:

   Future maintenance releases of BIND will correct the regression
   which introduced this issue but ISC does not believe that
   replacement security releases of BIND are required, given that
   several easy, safe, and completely effective configuration
   workarounds are available for any operators with affected
   configurations.  However, an advance version of the patch diff
   which will be applied to future versions is available upon request
   to security-officer at isc.org and a correction for the behavior
   in question will debut in the release candidates for BIND 9.9.13,
   BIND 9.10.8, BIND 9.11.4, and BIND 9.12.2.

Acknowledgements:

   ISC would like to thank Andrew Skalski for reporting this issue.

Document Revision History:

   1.0 Advance Notification 06 June 2018
   2.0 Public disclosure 12 June 2018

Related Documents:

   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:

  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
   http://www.isc.org/downloads/).

ISC Security Vulnerability Disclosure Policy:

   Details of our current security advisory policy and practice can
   be found here: https://kb.isc.org/article/AA-00861

This Knowledge Base article https://kb.isc.org/article/AA-01616 is
the complete and official security advisory document.

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.

(c) 2001-2018 Internet Systems Consortium

- --------------------------------------------------------------------------------

BIND 9.9.13 Release Notes

Author: Michael McNally Reference Number: AA-01632
Created: 2018-07-11 02:58
Last Updated: 2018-07-11 03:03

Introduction

This document summarizes significant changes since the last production release
of BIND on the corresponding major release branch. Please see the CHANGES file
for a further list of bug fixes and other changes.

Download

The latest versions of BIND 9 software can always be found at
http://www.isc.org/ downloads/. There you will find additional information about
each release, source code, and pre-compiled versions for Microsoft Windows
operating systems.

Legacy Windows No Longer Supported

As of BIND 9.9.11, Windows XP and Windows 2003 are no longer supported platforms
for BIND; "XP" binaries are no longer available for download from ISC.

Security Fixes

  * When recursion is enabled but the 
    allow-recursion and allow-query-cache ACLs are not specified, they should be
    limited to local networks, but they were inadvertently set to match the
    default allow-query, thus allowing remote queries. This flaw is disclosed in
    CVE-2018-5738. [GL #309]

New Features

  * named now supports the "root key
    sentinel" mechanism. This enables validating resolvers to indicate which
    Quick Jump Menu trust anchors are configured for the root, so that
    information about root key rollover status can be gathered.  To disable this
    feature, add root-key-sentinel no; to named.conf.
                                        
Feature Changes                         
                                        
  * None.                               
                                        
Bug Fixes                               
                                        
  * named now rejects excessively large
    incremental (IXFR) zone transfers in order to prevent possible corruption of
    journal files which could cause named to abort when loading zones. [GL #339]

  * rndc reload could cause named to leak
    memory if it was invoked before the zone loading actions from a previous
    rndc reload command were completed.  [RT #47076]

End of Life

BIND 9.9 (Extended Support Version) will be supported until June, 2018, at which
time this final maintenance release will be published for the branch. The new
Extended Support Version is BIND 9.11, which will be supported until at least
December, 2021. See https://www.isc.org/ downloads/software-support-policy/ for
details of ISC's software support policy.

- --------------------------------------------------------------------------------

BIND 9.10.8 Release Notes

Author: Michael McNally
Reference Number: AA-01633     
Created: 2018-07-11 02:50
Last Updated: 2018-07-11 03:02

Introduction

This document summarizes changes since the
last production release on the BIND 9.10
branch. Please see the CHANGES file for a
further list of bug fixes and other
changes.

Download

The latest versions of BIND 9 software can always be found at
http://www.isc.org/ downloads/. There you will find additional information about
each release, source code, and pre-compiled versions for Microsoft Windows
operating systems.

Legacy Windows No Longer Supported

As of BIND 9.10.6, Windows XP and Windows 2003 are no longer supported platforms
for BIND; "XP" binaries are no longer available for download from ISC.

Security Fixes

  * When recursion is enabled but the 
    allow-recursion and allow-query-cache ACLs are not specified, they should be
    limited to local networks, but they were inadvertently set to match the
    default allow-query, thus allowing remote queries. This flaw is disclosed in
    CVE-2018-5738. [GL #309]

New Features

  * named now supports the "root key
    sentinel" mechanism. This enables validating resolvers to indicate which
    trust anchors are configured for the root, so that information about root
    key rollover status can be gathered.  To disable this feature, add
    root-key-sentinel no; to named.conf.   [GL #37]
                                           
Feature Changes                            
                                           
  * None.                                  
                                           
Bug Fixes                                  
                                           
  * named now rejects excessively large    
    incremental (IXFR) zone transfers in order to prevent possible corruption
    of journal files which could cause named to abort when loading zones. [GL
    #339]

  * rndc reload could cause named to leak
    memory if it was invoked before the zone loading actions from a previous
    rndc reload command were completed.  [RT #47076]

End of Life

BIND 9.10 will be supported until June, 2018, at which time this final
maintenance release will be published for the branch.  For those needing
long-term support, the current Extended Support Version is BIND 9.11, which will
be supported until at least December, 2021. The current stable branch is BIND
9.12. See https:// www.isc.org/downloads/ software-support-policy/ for details
of ISC's software support policy.

- --------------------------------------------------------------------------------

BIND 9.11.4 Release Notes

Author: Michael McNally
Reference Number: AA-01634     
Created: 2018-07-11 02:51
Last Updated: 2018-07-11 03:03

Introduction

This document summarizes changes since the last production release on the BIND
9.11 (Extended Support Version) branch. Please see the CHANGES file for a
further list of bug fixes and other changes.

Download

The latest versions of BIND 9 software can always be found at
http://www.isc.org/ downloads/. There you will find additional information about
each release, source code, and pre-compiled versions for Microsoft Windows
operating systems.

License Change

With the release of BIND 9.11.0, ISC changed to the open source license for BIND
from the ISC license to the Mozilla Public License (MPL 2.0).

The MPL-2.0 license requires that if you make changes to licensed software (e.g.
BIND) and distribute them outside your organization, that you publish those
changes under that same license. It does not require that you publish or
disclose anything other than the changes you made to our software.

This requirement will not affect anyone who is using BIND, with or without
modifications, without redistributing it, nor anyone redistributing it without
changes. Therefore, this change will be without consequence for most individuals
and organizations who are using BIND.

Those unsure whether or not the license change affects their use of BIND, or who
wish to discuss how to comply with the license may contact ISC at https://
www.isc.org/mission/contact/.

Legacy Windows No Longer Supported

As of BIND 9.11.2, Windows XP and Windows 2003 are no longer supported platforms
for BIND; "XP" binaries are no longer available for download from ISC.

Security Fixes

  * When recursion is enabled but the 
    allow-recursion and allow-query-cache ACLs are not specified, they should be
    limited to local networks, but they were inadvertently set to match the
    default allow-query, thus allowing remote queries. This flaw is disclosed in
    CVE-2018-5738. [GL #309]

New Features

  * named now supports the "root key
    sentinel" mechanism. This enables validating resolvers to indicate which
    trust anchors are configured for the root, so that information about root
    key rollover status can be gathered. To disable this feature, add
    root-key-sentinel no; to named.conf.
                                           
  * Added the ability not to return a DNS  
    COOKIE option when one is present in the request. To prevent a cookie being
    returned, add answer-cookie no; to named.conf. [GL #173]                  
                                           
    answer-cookie no is only intended as a temporary measure, for use when named
    shares an IP address with other servers that do not yet support DNS
    COOKIE. A mismatch between servers on the same address is not expected to
    cause operational problems, but the option to disable COOKIE responses so
    that all servers have the same behavior is provided out of an abundance of
    caution. DNS COOKIE is an important security mechanism, and should not be
    disabled unless absolutely necessary.

Removed Features

  * named will now log a warning if the
    old BIND now can be compiled against libidn2 library to add IDNA2008
    support. Previously BIND only supported IDNA2003 using (now obsolete)
    idnkit-1 library.

Feature Changes

  * dig +noidnin can be used to disable
    IDN processing on the input domain name, when BIND is compiled with IDN
    support.

  * Multiple cookie-secret clause are now
    supported. The first cookie-secret in named.conf is used to generate new
    server cookies. Any others are used to accept old server cookies or those
    generated by other servers using the matching cookie-secret.

Bug Fixes

  * named now rejects excessively large
    incremental (IXFR) zone transfers in order to prevent possible corruption of
    journal files which could cause named to abort when loading zones. [GL #339]

  * rndc reload could cause named to leak
    memory if it was invoked before the zone loading actions from a previous
    rndc reload command were completed.  [RT #47076]

End of Life

BIND 9.11 (Extended Support Version) will be supported until at least December,
2021. See https://www.isc.org/downloads/ software-support-policy/ for details of
ISC's software support policy.

- --------------------------------------------------------------------------------

BIND 9.12.2 Release Notes

Author: Michael McNally Reference Number: AA-01635     Created: 2018-07-11 02:58
Last Updated: 2018-07-11 02:58

Introduction

This document summarizes changes since the last production release on the BIND
9.12 branch. Please see the CHANGES for a further list of bug fixes and other
changes.

Download

The latest versions of BIND 9 software can always be found at
http://www.isc.org/ downloads/. There you will find additional information about
each release, source code, and pre-compiled versions for Microsoft Windows
operating systems.

Security Fixes

  * When recursion is enabled but the 
    allow-recursion and allow-query-cache ACLs are not specified, they should be
    limited to local networks, but they were inadvertently set to match the
    default allow-query, thus allowing remote queries. This flaw is disclosed in
    CVE-2018-5738. [GL #309]

  * The serve-stale feature could cause an
    assertion failure in rbtdb.c even when stale-answer-enable was false. The
    simultaneous use of stale cache records and NSEC aggressive negative caching
    could trigger a recursion loop in the named process. This flaw is disclosed
    in CVE-2018-5737. [GL #185]

  * A bug in zone database reference
    counting could lead to a crash when multiple versions of a slave zone were
    transferred from a master in close succession. This flaw is disclosed in
    CVE-2018-5736. [GL #134]

New Features

  * update-policy rules that otherwise
    ignore the name field now require that it be set to "." to ensure that any
    type list present is properly interpreted. Previously, if the name field was
    omitted from the rule declaration but a type list was present, it wouldn't
    be interpreted as expected.

  * named now supports the "root key
    sentinel" mechanism. This enables validating resolvers to indicate which
    trust anchors are configured for the root, so that information about root
    key rollover status can be gathered.  To disable this feature, add
    root-key-sentinel no; to named.conf.  [GL #37]

  * Add the ability to not return a DNS
    COOKIE option when one is present in the request. To prevent a cookie being
    returned add answer-cookie no; to named.conf. [GL #173]

    answer-cookie no is only intended as a temporary measure, for use when named
    shares an IP address with other servers that do not yet support DNS
    COOKIE. A mismatch between servers on the same address is not expected to
    cause operational problems, but the option to disable COOKIE responses so
    that all servers have the same behavior is provided out of an
    abundance of caution. DNS COOKIE is an important security mechanism, and
    should not be disabled unless absolutely necessary.                 
                                           
Feature Changes
                                           
  * BIND now can be compiled against
    libidn2 library to add IDNA2008 support. Previously BIND only supported
    IDNA2003 using (now obsolete) idnkit-1 library.

  * dig +noidnin can be used to disable
    IDN processing on the input domain name, when BIND is compiled with IDN
    support.

Bug Fixes

  * named now rejects excessively large
    incremental (IXFR) zone transfers in order to prevent possible corruption of
    journal files which could cause named to abort when loading zones. [GL #339]

License

BIND is open source software licenced under the terms of the Mozilla Public
License, version 2.0 (see the LICENSE file for the full text).

The license requires that if you make changes to BIND and distribute them
outside your organization, those changes must be published under the same
license.  It does not require that you publish or disclose anything other than
the changes you have made to our software. This requirement does not affect
anyone who is using BIND, with or without modifications, without redistributing
it, nor anyone redistributing BIND without changes.

Those wishing to discuss license compliance may contact ISC at https://
www.isc.org/mission/contact/.

End of Life

The end-of-life date for BIND 9.12 has not yet been determined. However, it is
not intended to be an Extended Support Version (ESV) branch; accordingly,
support will end after the next stable branch (9.14) becomes available. Those
needing a longer-lived branch are encouraged to use the current ESV, BIND 9.11,
which will be supported until December 2021. See https:/ /www.isc.org/downloads/
software-support-policy/ for details of ISC's software support policy.

- --------------------------END INCLUDED TEXT--------------------

You have received this e-mail bulletin as a result of your organisation's
registration with AusCERT. The mailing list you are subscribed to is
maintained within your organisation, so if you do not wish to continue
receiving these bulletins you should contact your local IT manager. If
you do not know who that is, please send an email to auscert@auscert.org.au
and we will forward your request to the appropriate person.

NOTE: Third Party Rights
This security bulletin is provided as a service to AusCERT's members.  As
AusCERT did not write the document quoted above, AusCERT has had no control
over its content. The decision to follow or act on information or advice
contained in this security bulletin is the responsibility of each user or
organisation, and should be considered in accordance with your organisation's
site policies and procedures. AusCERT takes no responsibility for consequences
which may arise from following or acting on information or advice contained in
this security bulletin.

NOTE: This is only the original release of the security bulletin.  It may
not be updated when updates to the original are made.  If downloading at
a later date, it is recommended that the bulletin is retrieved directly
from the author's website to ensure that the information is still current.

Contact information for the authors of the original document is included
in the Security Bulletin above.  If you have any questions or need further
information, please contact them directly.

Previous advisories and external security bulletins can be retrieved from:

        https://www.auscert.org.au/bulletins/

===========================================================================
Australian Computer Emergency Response Team
The University of Queensland
Brisbane
Qld 4072

Internet Email: auscert@auscert.org.au
Facsimile:      (07) 3365 7031
Telephone:      (07) 3365 4417 (International: +61 7 3365 4417)
                AusCERT personnel answer during Queensland business hours
                which are GMT+10:00 (AEST).
                On call after hours for member emergencies only.
===========================================================================
-----BEGIN PGP SIGNATURE-----
Comment: http://www.auscert.org.au/render.html?it=1967
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=i1a8
-----END PGP SIGNATURE-----

« Back to bulletins