Bug 1438697 (CVE-2017-7393) - CVE-2017-7393 tigervnc: Double free via crafted fences
Summary: CVE-2017-7393 tigervnc: Double free via crafted fences
Alias: CVE-2017-7393
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
Target Milestone: ---
Assignee: Red Hat Product Security
QA Contact:
Whiteboard: impact=moderate,public=20170327,repor...
Keywords: Security
Depends On: 1438704 1439134
Blocks: 1415638 1438705
TreeView+ depends on / blocked
Reported: 2017-04-04 08:42 UTC by Andrej Nemec
Modified: 2019-06-11 11:13 UTC (History)
4 users (show)

A double free flaw was found in the way TigerVNC handled ClientFence messages. A remote, authenticated attacker could use this flaw to make Xvnc crash by sending specially crafted ClientFence messages, resulting in denial of service.
Clone Of:
Last Closed: 2019-06-08 03:09:51 UTC

Attachments (Terms of Use)

External Trackers
Tracker ID Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2017:2000 normal SHIPPED_LIVE Moderate: tigervnc and fltk security, bug fix, and enhancement update 2017-08-01 18:33:08 UTC

Description Andrej Nemec 2017-04-04 08:42:00 UTC
In TigerVNC (VNCSConnectionST.cxx VNCSConnectionST::fence), an authenticated client can cause a double free, leading to a crash of the TigerVNC server.

Upstream patch:


Upstream bug:


Comment 1 Andrej Nemec 2017-04-04 08:54:20 UTC
Created tigervnc tracking bugs for this issue:

Affects: fedora-all [bug 1438704]

Comment 4 errata-xmlrpc 2017-08-01 20:51:42 UTC
This issue has been addressed in the following products:

  Red Hat Enterprise Linux 7

Via RHSA-2017:2000 https://access.redhat.com/errata/RHSA-2017:2000

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