Bug 1839821 (CVE-2020-12667)

Summary:	CVE-2020-12667 knot-resolver: Traffic amplification triggered by random subdomains in the NSDNAME in NS records
Product:	[Other] Security Response	Reporter:	Pedro Sampaio <psampaio>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED UPSTREAM	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	jv+fedora, nicki, pspacek
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2020-05-25 21:15:24 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:	1839822, 1839823
Bug Blocks:

Description Pedro Sampaio 2020-05-25 16:43:47 UTC

Knot Resolver before 5.1.1 allows traffic amplification via a crafted DNS answer from an attacker-controlled server, aka an "NXNSAttack" issue. This is triggered by random subdomains in the NSDNAME in NS records.

References:

http://cyber-security-group.cs.tau.ac.il/#
http://www.openwall.com/lists/oss-security/2020/05/19/2
https://en.blog.nic.cz/2020/05/19/nxnsattack-upgrade-resolvers-to-stop-new-kind-of-random-subdomain-attack/
https://www.knot-resolver.cz/2020-05-19-knot-resolver-5.1.1.html

Comment 1 Pedro Sampaio 2020-05-25 16:44:17 UTC

Created knot-resolver tracking bugs for this issue:

Affects: epel-7 [bug 1839823]
Affects: fedora-all [bug 1839822]

Comment 2 Product Security DevOps Team 2020-05-25 21:15:24 UTC

This CVE Bugzilla entry is for community support informational purposes only as it does not affect a package in a commercially supported Red Hat product. Refer to the dependent bugs for status of those individual community products.