Bug 1661114 (CVE-2018-20019)

Summary:	CVE-2018-20019 libvncserver: Multiple heap out-of-bound writes in VNC client code
Product:	[Other] Security Response	Reporter:	Sam Fowler <sfowler>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	negativo17, ppisar, rdieter
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:	2021-10-25 22:22:22 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:	1661115, 1661116, 1663003, 1663007, 1671409, 1671410
Bug Blocks:	1661105

Description Sam Fowler 2018-12-20 07:03:09 UTC

LibVNC before commit a83439b9fbe0f03c48eb94ed05729cb016f8b72f contains multiple heap out-of-bound write vulnerabilities in VNC client code, which can result in remote code execution. This attack appears to be exploitable via network connectivity. This vulnerability has been fixed in a83439b9fbe0f03c48eb94ed05729cb016f8b72f and later.


External Reference:

https://ics-cert.kaspersky.com/advisories/klcert-advisories/2018/12/19/klcert-18-029-libvnc-multiple-heap-out-of-bound-vulnerabilities/


Upstream Patch:

https://github.com/LibVNC/libvncserver/commit/a83439b9fbe0f03c48eb94ed05729cb016f8b72f

Comment 1 Sam Fowler 2018-12-20 07:03:25 UTC

Created libvncserver tracking bugs for this issue:

Affects: epel-7 [bug 1661116]
Affects: fedora-all [bug 1661115]

Comment 2 Sam Fowler 2018-12-20 07:32:42 UTC

Upstream Issue:

https://github.com/LibVNC/libvncserver/issues/247

Comment 3 Stefan Cornelius 2018-12-21 11:44:56 UTC

Upstream patch is most likely problematic, for the same reasons as given in https://github.com/LibVNC/libvncserver/issues/273