|Summary:||CVE-2016-6170 bind: Improper restriction of zone size limit|
|Product:||[Other] Security Response||Reporter:||Adam Mariš <amaris>|
|Component:||vulnerability||Assignee:||Red Hat Product Security <security-response-team>|
|Status:||CLOSED WONTFIX||QA Contact:|
|Version:||unspecified||CC:||dkholia, jpopelka, msehnout, psimerda, rupatel, thozza, twalsh, vonsch, yozone, zdohnal|
|Fixed In Version:||Doc Type:||If docs needed, set a value|
It was found that bind does not implement reasonable restrictions for zone sizes. This allows an explicitly configured primary DNS server for a zone to crash a secondary DNS server, affecting service of other zones hosted on the same secondary server.
|Last Closed:||2016-09-19 05:09:39 UTC||Type:||---|
|oVirt Team:||---||RHEL 7.3 requirements from Atomic Host:|
|Cloudforms Team:||---||Target Upstream Version:|
|Bug Depends On:||1353569, 1353571|
Description Adam Mariš 2016-07-07 13:08:19 UTC
It was found that bind does not implement reasonable restrictions for zone sizes. This allows an explicitly configured primary DNS server for a zone to crash a secondary DNS server, affecting service of other zones hosted on the same secondary server. CVE request: http://seclists.org/oss-sec/2016/q3/19 Proposed patches: https://github.com/sischkg/xfer-limit/blob/master/bind-9.10.3-xfer-limit-0.0.1.patch https://github.com/sischkg/xfer-limit/blob/master/bind-9.9.9-P1-xfer-limit-0.0.1.patch
Comment 1 Adam Mariš 2016-07-07 13:13:28 UTC
Created bind tracking bugs for this issue: Affects: fedora-all [bug 1353569]
Comment 2 Adam Mariš 2016-07-07 13:13:33 UTC
Created bind99 tracking bugs for this issue: Affects: fedora-all [bug 1353571]
Comment 3 Tomáš Hozza 2016-07-15 08:44:22 UTC
Upstream solution: ISC wish to stress that the behavior in question is not a failure of BIND to implement DNS protocols correctly, but is if anything an oversight in the protocol. However, for the convenience of operators who take zone data from untrusted sources (such as secondary name service providers) we have committed to delivering a feature in upcoming maintenance releases of BIND which will address the issue by allowing operators to set limits on the maximum zone size BIND will accept. I checked the upstream git and there is no implementation yet.
Comment 4 Dhiru Kholia 2016-07-15 08:53:54 UTC
Mitigation: This issue can be mitigated by disallowing zone transfers and dynamic updates from potentially malicious sources. For more information, see the "Workarounds" section on https://kb.isc.org/article/AA-01390 page.
Comment 8 Dhiru Kholia 2016-09-19 05:08:11 UTC
Statement: Red Hat Product Security has rated this issue as having Low security impact. This issue is not currently planned to be addressed in future updates. For additional information, refer to the Issue Severity Classification: https://access.redhat.com/security/updates/classification/.