[Secure-testing-team] Bug#832483: Fix out of bound for viff file

[Bastien ROUCARIES]

Package: imagemagick
Version: 8:6.7.7.10-5
Severity: grave
Tags: patch security
X-Debbugs-CC: secure-testing-team at lists.alioth.debian.org


    Bug: https://github.com/ImageMagick/ImageMagick/issues/99
    Origin: upstream,
https://github.com/ImageMagick/ImageMagick/commit/ca0c886abd6d3ef335eb74150cd23b89ebd17135
    bug-ubuntu:
https://bugs.launchpad.net/ubuntu/+source/imagemagick/+bug/1537425
    bug-debian: https://bugs.debian.org/823750