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
Created bind tracking bugs for this issue: Affects: fedora-all [bug 1353569]
Created bind99 tracking bugs for this issue: Affects: fedora-all [bug 1353571]
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.
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.
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/.