N/A - GLSA-201810-04

Synopsis

Due to multiple vulnerabilities in various coders used by ImageMagick, Gentoo Linux now installs a policy.xml file which will restrict coder usage by default.

Background

ImageMagick is a collection of tools and libraries for many image formats.

Description

If you process an image with ImageMagick and don't validate the file before (e.g. check magic byte), ImageMagick will call any coders found in the given file. So if ImageMagick will find Ghostscript for example, it will call Ghostscript.

Due to multiple -dSAFER sandbox bypass vulnerabilities in Ghostscript, this can lead to arbitrary code execution.

To mitigate this problem we install a policy.xml file by default which will disable PS, EPS, PDF, and XPS coders.

Impact

A remote attacker, by enticing a user to process a specially crafted image file, could execute arbitrary code with the privileges of the process or cause a Denial of Service condition.

Workaround

There is no known workaround at this time.

Resolution

All ImageMagick 6 users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot -v ">=media-gfx/imagemagick-6.9.10.10-r1"

All ImageMagick 7 users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot -v ">=media-gfx/imagemagick-7.0.8.10-r1"

References

[ 1 ] Ghostscript contains multiple -dSAFER sandbox bypass vulnerabilities (VU#332928)
https://www.kb.cert.org/vuls/id/332928

Availability

This GLSA and any updates to it are available for viewing at the Gentoo Security Website:

https://security.gentoo.org/glsa/201810-04