Bug 1813867 (CVE-2020-11653)

Summary:	CVE-2020-11653 varnish: remote clients may cause Varnish to assert and restart which could result in DoS
Product:	[Other] Security Response	Reporter:	Michael Kaplan <mkaplan>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	hhorak, ingvar, jorton, luhliari
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	varnish 6.2.3, varnish 6.3.2	Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2020-11-04 02:24:46 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:	1813869, 1813870, 1819936, 1819937, 1820205
Bug Blocks:	1813873

Description Michael Kaplan 2020-03-16 10:45:20 UTC

An assert can be triggered in Varnish Cache when using Varnish with a TLS termination proxy, and the proxy and Varnish use the PROXY version 2. The assert will cause Varnish to restart, and the cache will be empty after the restart.

Upstream Reference:

https://varnish-cache.org/security/VSV00005.html#vsv00005

Comment 1 Michael Kaplan 2020-03-16 11:00:13 UTC

Created varnish tracking bugs for this issue:

Affects: epel-all [bug 1813870]
Affects: fedora-all [bug 1813869]

Comment 2 Ingvar Hagelund 2020-03-16 13:53:40 UTC

This was fixed in fedora 32 on 2020-02-10. Unfortunately, I forgot to make updates for f31 and f30. 

I have generated FEDORA-2020-872ec29251 (f30) and FEDORA-2020-71ca06dd55 (f31) now. Please test and leave karma.

https://bodhi.fedoraproject.org/updates/FEDORA-2020-872ec29251
https://bodhi.fedoraproject.org/updates/FEDORA-2020-71ca06dd55


Ingvar

Comment 3 Joe Orton 2020-03-16 14:48:47 UTC

Ingvar, thanks for pushing updates.

FYI - the state for the "Security Response" vulnerability tracker bugs should be left to be managed by the security team.

Comment 4 Marco Benatto 2020-04-01 20:55:49 UTC

Upstream commit for this issue:
https://github.com/varnishcache/varnish-cache/commit/2d8fc1a784a1e26d78c30174923a2b14ee2ebf62

Comment 7 Marco Benatto 2020-04-01 21:08:19 UTC

External References:

https://varnish-cache.org/security/VSV00005.html#vsv00005

Comment 11 Marco Benatto 2020-04-08 12:25:20 UTC

Mitigation:

An user can mitigate the problem by setting the proxy protocol to version 1 on the TLS Proxy side, as this flaw only affects the proxy protocol version 2.

Comment 13 Product Security DevOps Team 2020-11-04 02:24:46 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-2020-11653

Comment 14 errata-xmlrpc 2020-11-04 03:38:41 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2020:4756 https://access.redhat.com/errata/RHSA-2020:4756