Bug 2064514 (CVE-2022-0635)

Summary:	CVE-2022-0635 bind: Lookups involving a DNAME could trigger an assertion failure when 'synth-from-dnssec' was enabled (which is the default)
Product:	[Other] Security Response	Reporter:	TEJ RATHI <trathi>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED NOTABUG	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
Version:	unspecified	CC:	anon.amish, dns-sig, jorton, mosvald, mruprich, pavel, pemensik, security-response-team, vonsch, yozone, zdohnal
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	bind 9.18.1	Doc Type:	If docs needed, set a value
Doc Text:	An assertion check flaw was found in BIND, with a refactoration of RFC 8198 Aggressive Use of the DNSSEC-Validated Cache feature (synth-from-dnssec). The repeated patterns of specific queries to servers with this feature enabled could cause an INSIST failure in query.c:query_dname, which results in unexpected termination. This flaw allows a remote attacker to use a series of specific queries to trigger a failed assertion check that causes the named process to terminate, leading to a denial of service.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2022-04-06 13:27:40 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:	2064517

Description TEJ RATHI 2022-03-16 04:42:13 UTC

We refactored the RFC 8198 Aggressive Use of DNSSEC-Validated Cache feature (synth-from-dnssec) for the new BIND 9.18.0 stable release, and changed the default so that is now automatically enabled for dnssec-validating resolvers. Subsequently it was found that repeated patterns of specific queries to servers with this feature enabled could cause an INSIST failure in query.c:query_dname which causes named to terminate unexpectedly.

The vulnerability affects BIND resolvers running 9.18.0 that have both dnssec-validation and synth-from-dnssec enabled. (Note that dnssec-validation auto; is the default setting unless configured otherwise in named.conf and that enabling dnssec-validation automatically enables synth-from-dnssec unless explicitly disabled)

Comment 4 Product Security DevOps Team 2022-04-06 13:27:38 UTC

This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):

https://access.redhat.com/security/cve/cve-2022-0635