Bug 1847242 (CVE-2020-8618)

Summary:	CVE-2020-8618 bind: A buffer boundary check assertion in rdataset.c can fail incorrectly during zone transfer
Product:	[Other] Security Response	Reporter:	Huzaifa S. Sidhpurwala <huzaifas>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED NOTABUG	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	aegorenk, anon.amish, carnil, 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 9.16.4	Doc Type:	If docs needed, set a value
Doc Text:	An assertion check flaw caused by a buffer boundary check condition was found in BIND. A remote attacker could trigger this flaw via a large response, during zone transfer. The highest threat from this vulnerability is to system availability.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2020-06-18 05:20:21 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:	1847243

Description Huzaifa S. Sidhpurwala 2020-06-16 04:11:06 UTC

As per upstream advisory:

An assertion check in BIND (that is meant to prevent going beyond the end of a buffer when processing incoming data) can be incorrectly triggered by a large response during zone transfer.

An attacker who is permitted to send zone data to a server via zone transfer can exploit this to intentionally trigger the assertion failure with a specially constructed zone, denying service to clients.

This flaw only affects bind-9.16 branch, other versions are not affected.

Comment 1 Huzaifa S. Sidhpurwala 2020-06-16 04:11:12 UTC

Acknowledgments:

Name: ISC

Comment 3 RaTasha Tillery-Smith 2020-06-16 14:33:18 UTC

Statement:

This flaw only affects bind-9.16.x, therefore versions of BIND shipped with Red Hat Products are not affected by this flaw.

Comment 4 Huzaifa S. Sidhpurwala 2020-06-18 05:06:18 UTC

External References:

https://kb.isc.org/docs/cve-2020-8618

Comment 5 Product Security DevOps Team 2020-06-18 05:20:21 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-2020-8618

Comment 7 Salvatore Bonaccorso 2020-06-19 09:20:13 UTC

Hi Huzaifa,

(In reply to Huzaifa S. Sidhpurwala from comment #6)
> Upstream bug: https://gitlab.isc.org/isc-projects/bind9/-/issues/1718
> Upstream commit:
> https://gitlab.isc.org/isc-projects/bind9/-/commit/
> 569cc155b8680d8ed12db1fabbe20947db24a0f9

In the above references the upstream bug seem actually for CVE-2020-8619. Not sure about the commit.

Regards,
Salvatore

Comment 8 Salvatore Bonaccorso 2020-06-19 09:22:47 UTC

(In reply to Salvatore Bonaccorso from comment #7)
> Hi Huzaifa,
> 
> (In reply to Huzaifa S. Sidhpurwala from comment #6)
> > Upstream bug: https://gitlab.isc.org/isc-projects/bind9/-/issues/1718
> > Upstream commit:
> > https://gitlab.isc.org/isc-projects/bind9/-/commit/
> > 569cc155b8680d8ed12db1fabbe20947db24a0f9
> 
> In the above references the upstream bug seem actually for CVE-2020-8619.
> Not sure about the commit.

The upstream issue is at https://gitlab.isc.org/isc-projects/bind9/-/issues/1850

Comment 9 Huzaifa S. Sidhpurwala 2020-06-19 09:49:48 UTC

(In reply to Salvatore Bonaccorso from comment #7)
> Hi Huzaifa,
> 
> (In reply to Huzaifa S. Sidhpurwala from comment #6)
> > Upstream bug: https://gitlab.isc.org/isc-projects/bind9/-/issues/1718
> > Upstream commit:
> > https://gitlab.isc.org/isc-projects/bind9/-/commit/
> > 569cc155b8680d8ed12db1fabbe20947db24a0f9
> 
> In the above references the upstream bug seem actually for CVE-2020-8619.
> Not sure about the commit.
> 
> Regards,
> Salvatore

Yes, thanks for noticing.