Bug 1466189 (CVE-2017-3142)

Summary: CVE-2017-3142 bind: An error in TSIG authentication can permit unauthorized zone transfers
Product: [Other] Security Response Reporter: Adam Mariš <amaris>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED ERRATA QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: dkholia, jpopelka, mruprich, msehnout, pavlix, pemensik, security-response-team, slawomir, thozza, vonsch, yozone, zdohnal
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: bind 9.9.10-P2, bind 9.10.5-P2,bind 9.11.1-P2 Doc Type: If docs needed, set a value
Doc Text:
A flaw was found in the way BIND handled TSIG authentication of AXFR requests. A remote attacker, able to communicate with an authoritative BIND server, could use this flaw to view the entire contents of a zone by sending a specially constructed request packet.
Story Points: ---
Clone Of: Environment:
Last Closed: 2017-07-06 08:26:01 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Bug Depends On: 1466201, 1466202, 1466203, 1466204, 1466611, 1466612, 1466805    
Bug Blocks: 1466195    

Description Adam Mariš 2017-06-29 08:42:20 UTC
An attacker able to send and receive messages to an authoritative DNS server may be able to circumvent TSIG authentication of AXFR requests via a carefully constructed request packet. A server that relies solely on TSIG keys for protection with no other ACL protection could be manipulated into:

* providing an AXFR of a zone to an unauthorized recipient
* accepting bogus Notify packets

An unauthorized AXFR (full zone transfer) permits an attacker to view the entire contents of a zone.  Protection of zone contents is often a commercial or business requirement.

If accepted, a Notify sets the zone refresh interval to 'now'. If there is not already a refresh cycle in progress then named will initiate one by asking for the SOA RR from its list of masters.  If there is already a refresh cycle in progress, then named will queue the new refresh request.  If there is already a queued refresh request, the new Notify will be discarded. Bogus notifications can't be used to force a zone transfer from a malicious server, but could trigger a high rate of zone refresh cycles.


Workarounds:

The effects of this vulnerability can be mitigated by using Access Control Lists (ACLs) that require both address range validation and use of TSIG authentication in parallel. For information on how to configure this type of compound authentication control, please see:

https://kb.isc.org/article/AA-00723/0/Using-Access-Control-Lists-ACLs-with-both-addresses-and-keys.html.

(Note that this technique will not be effective against bogus Notify packets if an attacker is able to reach the target DNS server whilst using a spoofed sending address).


Upstream patch:

https://source.isc.org/cgi-bin/gitweb.cgi?p=bind9.git;a=commitdiff;h=581c1526ab

Comment 1 Adam Mariš 2017-06-29 08:42:26 UTC
Acknowledgments:

Name: Internet Systems Consortium
Upstream: Clement Berthaux (Synacktiv)

Comment 3 Dhiru Kholia 2017-06-30 04:23:01 UTC
External References:

https://kb.isc.org/article/AA-01504

Comment 4 Dhiru Kholia 2017-06-30 04:26:23 UTC
Created bind tracking bugs for this issue:

Affects: fedora-all [bug 1466611]


Created bind99 tracking bugs for this issue:

Affects: fedora-all [bug 1466612]

Comment 7 Dhiru Kholia 2017-07-03 10:28:12 UTC
Mitigation:

The effects of this vulnerability can be mitigated by using Access Control Lists (ACLs) that require both address range validation and use of TSIG authentication in parallel. For information on how to configure this type of compound authentication control, please see:

https://kb.isc.org/article/AA-00723/0/Using-Access-Control-Lists-ACLs-with-both-addresses-and-keys.html

Comment 8 errata-xmlrpc 2017-07-05 09:17:03 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2017:1680 https://access.redhat.com/errata/RHSA-2017:1680

Comment 9 errata-xmlrpc 2017-07-05 09:27:10 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 6

Via RHSA-2017:1679 https://access.redhat.com/errata/RHSA-2017:1679