Bug 1702642 (CVE-2019-6468)

Summary: CVE-2019-6468 bind: named can exit with an assertion failure if nxdomain-redirect is used.
Product: [Other] Security Response Reporter: Huzaifa S. Sidhpurwala <huzaifas>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED NOTABUG QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: anon.amish, jpopelka, mruprich, msehnout, pemensik, pzhukov, security-response-team, thozza, vonsch, zdohnal
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: bind 9.11.5-S6 Doc Type: If docs needed, set a value
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2019-04-25 05:24:45 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 1702542    

Description Huzaifa S. Sidhpurwala 2019-04-24 10:59:24 UTC 
As per upstream advisory:

In BIND Supported Preview Edition, an error in the nxdomain-redirect feature can occur in versions which support EDNS Client Subnet (ECS) features. In those versions which have ECS support, enabling nxdomain-redirect is likely to lead to BIND exiting due to assertion failure.

If nxdomain-redirect is enabled (via configuration) in a vulnerable BIND release, a malicious party can cause BIND to exit by deliberately triggering the bug.
Comment 1 Huzaifa S. Sidhpurwala 2019-04-24 10:59:29 UTC 
Acknowledgments:

Name: ISC
Comment 2 Huzaifa S. Sidhpurwala 2019-04-24 11:00:47 UTC 
Statement:

This issue only affects the special feature preview branch of bind. Bind packages shipped with Red Hat Enterprise Linux are not affected by this flaw.
Comment 3 Huzaifa S. Sidhpurwala 2019-04-25 05:24:49 UTC 
External References:

https://kb.isc.org/docs/cve-2019-6468