Bug 1438697 (CVE-2017-7393)

Summary:	CVE-2017-7393 tigervnc: Double free via crafted fences
Product:	[Other] Security Response	Reporter:	Andrej Nemec <anemec>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	bphinz, jgrulich, slawomir, twaugh
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:	A double free flaw was found in the way TigerVNC handled ClientFence messages. A remote, authenticated attacker could use this flaw to make Xvnc crash by sending specially crafted ClientFence messages, resulting in denial of service.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2019-06-08 03:09:51 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:	1438704, 1439134
Bug Blocks:	1415638, 1438705

Description Andrej Nemec 2017-04-04 08:42:00 UTC

In TigerVNC (VNCSConnectionST.cxx VNCSConnectionST::fence), an authenticated client can cause a double free, leading to a crash of the TigerVNC server.

Upstream patch:

https://github.com/TigerVNC/tigervnc/pull/438/commits/f3afa24da144409a3c3a0e35913112583d987671

Upstream bug:

https://github.com/TigerVNC/tigervnc/issues/437

Comment 1 Andrej Nemec 2017-04-04 08:54:20 UTC

Created tigervnc tracking bugs for this issue:

Affects: fedora-all [bug 1438704]

Comment 4 errata-xmlrpc 2017-08-01 20:51:42 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2017:2000 https://access.redhat.com/errata/RHSA-2017:2000