Bug 1860348 (CVE-2020-14398)

Summary:	CVE-2020-14398 libvncserver: an improperly closed TCP connection causes an infinite loop in libvncclient/sockets.c
Product:	[Other] Security Response	Reporter:	Marian Rehak <mrehak>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED WONTFIX	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	jadahl, negativo17, oholy, rdieter
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	libvncserver 0.9.13	Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2021-11-02 17:20:05 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:	1860349, 1860350, 1861156, 1861157
Bug Blocks:	1860332

Description Marian Rehak 2020-07-24 10:57:16 UTC

An issue was discovered in LibVNCServer before 0.9.13. An improperly closed TCP connection causes an infinite loop in libvncclient/sockets.c.

Upstream commit:

https://github.com/LibVNC/libvncserver/commit/57433015f856cc12753378254ce4f1c78f5d9c7b

Comment 1 Marian Rehak 2020-07-24 10:57:41 UTC

Created libvncserver tracking bugs for this issue:

Affects: epel-7 [bug 1860350]
Affects: fedora-all [bug 1860349]

Comment 2 Todd Cullum 2020-07-27 23:26:15 UTC

Statement:

This flaw does not affect versions of vino shipped with Red Hat Enterprise Linux 6, 7, or 8 because libvncclient is not included in the package.

Comment 3 Todd Cullum 2020-07-27 23:30:02 UTC

This flaw affects libvncclient, which is shipped with libvncserver. It can be triggered by killing the process, cutting powerful, or another means of ungraceful shutdown causing the TCP connection to be improperly closed.