Bug 1661120 (CVE-2018-20021) - CVE-2018-20021 libvncserver: Infinite loop in VNC client code allows for denial of service
Summary: CVE-2018-20021 libvncserver: Infinite loop in VNC client code allows for deni...
Keywords:
Status: CLOSED WONTFIX
Alias: CVE-2018-20021
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
low
low
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
URL:
Whiteboard:
Depends On: 1661122 1661121 1663001
Blocks: 1661105
TreeView+ depends on / blocked
 
Reported: 2018-12-20 07:09 UTC by Sam Fowler
Modified: 2019-09-29 15:04 UTC (History)
3 users (show)

Fixed In Version:
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Last Closed: 2019-06-10 10:44:24 UTC


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Description Sam Fowler 2018-12-20 07:09:10 UTC
LibVNC before commit c3115350eb8bb635d0fdb4dbbb0d0541f38ed19c contains a CWE-835: Infinite loop vulnerability in VNC client code. Vulnerability allows attacker to consume excessive amount of resources like CPU and RAM


External Reference:

https://ics-cert.kaspersky.com/advisories/klcert-advisories/2018/12/19/klcert-18-031-libvnc-infinite-loop/


Upstream Patch:

https://github.com/LibVNC/libvncserver/commit/c3115350eb8bb635d0fdb4dbbb0d0541f38ed19c

Comment 1 Sam Fowler 2018-12-20 07:09:24 UTC
Created libvncserver tracking bugs for this issue:

Affects: epel-7 [bug 1661122]
Affects: fedora-all [bug 1661121]

Comment 2 Sam Fowler 2018-12-20 07:40:16 UTC
Upstream Issue:

https://github.com/LibVNC/libvncserver/issues/251

Comment 3 Stefan Cornelius 2018-12-21 11:05:54 UTC
I suspect that this was introduced by https://github.com/LibVNC/libvncserver/commit/79d938c16bf7a14b6d6ee290bcfef3c01f9c4f02 - which fixed a divbyzero.


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