Bug 1789908 (CVE-2019-15691)

Summary:	CVE-2019-15691 tigervnc: Stack use-after-return due to incorrect usage of stack memory in ZRLEDecoder
Product:	[Other] Security Response	Reporter:	Guilherme de Almeida Suckevicz <gsuckevi>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	fedora, jgrulich, twaugh, vonsch
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:	2020-04-16 22:31:52 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:	1789909, 1791759, 1791760, 1819884, 1819885
Bug Blocks:	1789910, 1790319

Description Guilherme de Almeida Suckevicz 2020-01-10 17:13:29 UTC

TigerVNC version prior to 1.10.1 is vulnerable to stack use-after-return, which occurs due to incorrect usage of stack memory in ZRLEDecoder. If decoding routine would throw an exception, ZRLEDecoder may try to access stack variable, which has been already freed during the process of stack unwinding. Exploitation of this vulnerability could potentially result into remote code execution. This attack appear to be exploitable via network connectivity.

Reference and upstream commit:
https://github.com/CendioOssman/tigervnc/commit/d61a767d6842b530ffb532ddd5a3d233119aad40

Comment 1 Guilherme de Almeida Suckevicz 2020-01-10 17:13:44 UTC

Created tigervnc tracking bugs for this issue:

Affects: fedora-all [bug 1789909]

Comment 2 Huzaifa S. Sidhpurwala 2020-01-16 12:37:44 UTC

https://github.com/TigerVNC/tigervnc/pull/921

As per upstream " All issues require a successfully authenticated connection though."

Comment 4 errata-xmlrpc 2020-04-16 21:06:28 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2020:1497 https://access.redhat.com/errata/RHSA-2020:1497

Comment 5 Product Security DevOps Team 2020-04-16 22:31:52 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-2019-15691

Comment 6 errata-xmlrpc 2020-09-29 19:27:43 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2020:3875 https://access.redhat.com/errata/RHSA-2020:3875