Bug 1418944 (CVE-2017-5884) - CVE-2017-5884 gtk-vnc: Improper check of framebuffer boundaries when processing a tile
Summary: CVE-2017-5884 gtk-vnc: Improper check of framebuffer boundaries when processi...
Keywords:
Status: CLOSED ERRATA
Alias: CVE-2017-5884
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: 1418955 1418956 1425367
Blocks: 1415638 1418954
TreeView+ depends on / blocked
 
Reported: 2017-02-03 08:52 UTC by Adam Mariš
Modified: 2019-09-29 14:06 UTC (History)
16 users (show)

Fixed In Version:
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Doc Text:
It was found that gtk-vnc lacked proper bounds checking while processing messages using RRE, hextile, or copyrect encodings. A remote malicious VNC server could use this flaw to crash VNC viewers which are based on the gtk-vnc library.
Clone Of:
Environment:
Last Closed: 2019-06-08 03:06:59 UTC
Embargoed:

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Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2017:2258 0 normal SHIPPED_LIVE Moderate: gtk-vnc security, bug fix, and enhancement update 2017-08-01 18:21:01 UTC

Description Adam Mariš 2017-02-03 08:52:02 UTC 
It was found that gtk-vnc does not properly check boundaries of subrectangle-containing tiles. A malicious server can use this to overwrite parts of the client memory, potentially leading to code execution under privileges of the user running the VNC client.

Upstream bug:

https://bugzilla.gnome.org/show_bug.cgi?id=778048

Upstream patch:

https://git.gnome.org/browse/gtk-vnc/commit/?id=ea0386933214c9178
Comment 1 Adam Mariš 2017-02-03 09:12:42 UTC 
Created gtk-vnc tracking bugs for this issue:

Affects: fedora-all [bug 1418955]
Comment 2 Adam Mariš 2017-02-03 09:13:00 UTC 
Created mingw-gtk-vnc tracking bugs for this issue:

Affects: fedora-all [bug 1418956]
Comment 3 Adam Mariš 2017-02-06 08:45:06 UTC 
CVE assignment:

http://openwall.com/lists/oss-security/2017/02/05/5

CVE covers all issues mentioned in https://bugzilla.gnome.org/show_bug.cgi?id=778048#c1
Comment 4 Daniel Berrangé 2017-02-07 14:13:49 UTC 
Upstream fix in git master is

commit ea0386933214c9178aaea9f2f85049ea3fa3e14a
Author: Daniel P. Berrange <berrange>
Date:   Thu Feb 2 17:34:47 2017 +0000

    Fix bounds checking for RRE, hextile & copyrect encodings
    
    While the client would bounds check the overall update
    region, it failed to bounds check the payload data
    parameters.
    
    Add a test case to validate bounds checking.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=778048
    
    CVE-2017-5884
    
    Signed-off-by: Daniel P. Berrange <berrange>
Comment 10 errata-xmlrpc 2017-08-01 19:56:49 UTC 
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2017:2258 https://access.redhat.com/errata/RHSA-2017:2258
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