Bug 1033468 - (CVE-2017-3138) VUL-0: CVE-2017-3138: bind: named exits with a REQUIRE assertion failure if it receives a null command string on its control channel
(CVE-2017-3138)
VUL-0: CVE-2017-3138: bind: named exits with a REQUIRE assertion failure if i...
Status: RESOLVED FIXED
Classification: Novell Products
Product: SUSE Security Incidents
Classification: Novell Products
Component: Incidents
unspecified
Other Other
: P3 - Medium : Normal
: ---
Assigned To: Navin Kukreja
Security Team bot
CVSSv2:SUSE:CVE-2017-3138:5.0:(AV:N/A...
:
Depends on:
Blocks: 1033461
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Reported: 2017-04-11 07:18 UTC by Alexander Bergmann
Modified: 2020-09-24 14:55 UTC (History)
4 users (show)

See Also:
Found By: ---
Services Priority:
Business Priority:
Blocker: ---
Marketing QA Status: ---
IT Deployment: ---


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Comment 1 Vítězslav Čížek 2017-04-11 13:51:06 UTC
Reading the Description/Impact section above, we're not affected by this bug.
Once the "attacker" has access to the control channel, he can simply stop the server by using "rndc stop".
The "read only" operations option, which limits the allowed commands to non-destructive only, was introduced in bind 9.11.0.
We don't ship bind 9.11 in any distribution.
Comment 6 Swamp Workflow Management 2017-04-13 04:10:21 UTC
SUSE-SU-2017:0998-1: An update that solves 5 vulnerabilities and has one errata is now available.

Category: security (important)
Bug References: 1020983,1033466,1033467,1033468,987866,989528
CVE References: CVE-2016-2775,CVE-2016-6170,CVE-2017-3136,CVE-2017-3137,CVE-2017-3138
Sources used:
SUSE Linux Enterprise Software Development Kit 12-SP2 (src):    bind-9.9.9P1-59.1
SUSE Linux Enterprise Software Development Kit 12-SP1 (src):    bind-9.9.9P1-59.1
SUSE Linux Enterprise Server for Raspberry Pi 12-SP2 (src):    bind-9.9.9P1-59.1
SUSE Linux Enterprise Server 12-SP2 (src):    bind-9.9.9P1-59.1
SUSE Linux Enterprise Server 12-SP1 (src):    bind-9.9.9P1-59.1
SUSE Linux Enterprise Desktop 12-SP2 (src):    bind-9.9.9P1-59.1
SUSE Linux Enterprise Desktop 12-SP1 (src):    bind-9.9.9P1-59.1
Comment 7 Swamp Workflow Management 2017-04-13 04:11:24 UTC
SUSE-SU-2017:0999-1: An update that fixes 5 vulnerabilities is now available.

Category: security (important)
Bug References: 1033466,1033467,1033468,987866,989528
CVE References: CVE-2016-2775,CVE-2016-6170,CVE-2017-3136,CVE-2017-3137,CVE-2017-3138
Sources used:
SUSE Linux Enterprise Server for SAP 12 (src):    bind-9.9.9P1-28.34.1
SUSE Linux Enterprise Server 12-LTSS (src):    bind-9.9.9P1-28.34.1
Comment 8 Swamp Workflow Management 2017-04-13 04:12:31 UTC
SUSE-SU-2017:1000-1: An update that fixes 5 vulnerabilities is now available.

Category: security (important)
Bug References: 1033466,1033467,1033468,987866,989528
CVE References: CVE-2016-2775,CVE-2016-6170,CVE-2017-3136,CVE-2017-3137,CVE-2017-3138
Sources used:
SUSE OpenStack Cloud 5 (src):    bind-9.9.6P1-0.44.1
SUSE Manager Proxy 2.1 (src):    bind-9.9.6P1-0.44.1
SUSE Manager 2.1 (src):    bind-9.9.6P1-0.44.1
SUSE Linux Enterprise Software Development Kit 11-SP4 (src):    bind-9.9.6P1-0.44.1
SUSE Linux Enterprise Server 11-SP4 (src):    bind-9.9.6P1-0.44.1
SUSE Linux Enterprise Server 11-SP3-LTSS (src):    bind-9.9.6P1-0.44.1
SUSE Linux Enterprise Point of Sale 11-SP3 (src):    bind-9.9.6P1-0.44.1
SUSE Linux Enterprise Debuginfo 11-SP4 (src):    bind-9.9.6P1-0.44.1
SUSE Linux Enterprise Debuginfo 11-SP3 (src):    bind-9.9.6P1-0.44.1
Comment 9 Marcus Meissner 2017-04-13 06:54:46 UTC
Please also submit fixes to openSUSE Leap and Factory now.
Comment 10 Marcus Meissner 2017-04-13 07:04:50 UTC
https://kb.isc.org/article/AA-01471/0

CVE-2017-3138: named exits with a REQUIRE assertion failure if it receives a null command string on its control channel
Author: Michael McNally Reference Number: AA-01471 Views: 1376 Created: 2017-04-12 17:30 Last Updated: 2017-04-12 23:35 	0 Rating/ Voters 	

CVE: 
CVE-2017-3138
Document Version: 
2.0
Posting date: 
12 April 2017
Program Impacted: 
BIND
Versions affected: 
9.9.9->9.9.9-P7, 9.9.10b1->9.9.10rc2, 9.10.4->9.10.4-P7, 9.10.5b1->9.10.5rc2, 9.11.0->9.11.0-P4, 9.11.1b1->9.11.1rc2, 9.9.9-S1->9.9.9-S9
Severity:
Medium
Exploitable: 
Remotely, from hosts that are within the ACL permitted access to the control channel

Description:

named contains a feature which allows operators to issue commands to a running server by communicating with the server process over a control channel, using a utility program such as rndc.

A regression introduced in a recent feature change has created a situation under which some versions of named can be caused to exit with a REQUIRE assertion failure if they are sent a null command string.

Impact:

The BIND control channel is not configured by default, but when configured will accept commands from those IP addresses that are specified in its access control list and/or from clients which present the proper transaction key.  Using this defect, an attacker can cause a running server to stop if they can get it to accept control channel input from them.  In most instances this is not as bad as it sounds, because existing commands permitted over the control channel (i.e. "rndc stop") can already be given to cause the server to stop.

However, BIND 9.11.0 introduced a new option to allow "read only" commands over the command channel.  Using this restriction, a server can be configured to limit specified clients to giving control channel commands which return information only (e.g. "rndc status") without affecting the operational state of the server.  The defect described in this advisory, however, is not properly stopped by the "read only" restriction, in essence permitting a privilege escalation allowing a client which should only be permitted the limited set of "read only" operations to cause the server to stop execution.

CVSS Score:  6.5

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

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:L/UI:N/S:U/C:N/I:N/A:H

Workarounds:

None.  However, in a properly configured server, access to the control channel should already be limited by either network ACLs, TSIG keys, or both.

Active exploits:

No known active exploits

Solution:  Upgrade to the patched release most closely related to your current version of BIND. These can all be downloaded from http://www.isc.org/downloads.

    BIND 9 version 9.9.9-P8
    BIND 9 version 9.10.4-P8
    BIND 9 version 9.11.0-P5

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

    BIND 9 version 9.9.9-S10

New maintenance releases of BIND are also scheduled which contain the fix for this vulnerability.  In addition to the security releases listed above, fixes for this vulnerability are also included in these release candidate versions:

    BIND 9 version 9.9.10rc3
    BIND 9 version 9.10.5rc3
    BIND 9 version 9.11.1rc3

Acknowledgements: ISC would like to thank Mike Lalumiere of Dyn, Inc., for bringing this issue to our attention.

Document Revision History:

1.0 Advance Notification 20 March 2017
1.1 Revised Acknowledgements and Versions Affected 22 March 2017
1.2 Added mention of maintenance releases to the Solution section 31 March 2017
2.0 Public Announcement 12 April 2017
Comment 12 Swamp Workflow Management 2017-04-19 19:09:58 UTC
openSUSE-SU-2017:1063-1: An update that solves 5 vulnerabilities and has one errata is now available.

Category: security (important)
Bug References: 1020983,1033466,1033467,1033468,987866,989528
CVE References: CVE-2016-2775,CVE-2016-6170,CVE-2017-3136,CVE-2017-3137,CVE-2017-3138
Sources used:
openSUSE Leap 42.2 (src):    bind-9.9.9P1-48.3.1
openSUSE Leap 42.1 (src):    bind-9.9.9P1-51.1
Comment 15 Navin Kukreja 2017-07-05 09:44:07 UTC
We have bind-9.3.4 in SLE-10-SP3 and bind-9.6-ESV in SLE-11. CVE description says they are not affected. The following commit is to fix CVE-2017-3138.

    4582.   [security]      'rndc ""' could trigger a assertion failure in named.
                            (CVE-2017-3138) [RT #44924]

The fix is in isc_lex_create() function and in affected versions, the main handler that processes control channel messages (ns_control_docommand) calls isc_lex_create

        result = isc_lex_create(ns_g_mctx, strlen(cmdline), &lex);
        if (result != ISC_R_SUCCESS)
                return (result);
"bin/named/control.c" 293 lines --34%--

However, in bind-9.3.4 and bind-9.6-ESV, there is no call to isc_lex_create() under ns_control_docommand(). The above fix won't do anything.

I don't think we need backport it to SLE-10-SP3 & bind-9.6-ESV.
Comment 16 Marcus Meissner 2017-07-05 09:48:32 UTC
thanks! then I think we are done.