CVE-2020-27756 Denial of service in ImageMagick
A crafted image file can cause a divide-by-zero error in ImageMagick, leading to application crashes and denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2020-27756?
CVE-2020-27756 is a medium-severity denial of service vulnerability in Imagemagick Imagemagick, published on 8 Dec 2020. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
In ParseMetaGeometry() of MagickCore/geometry.c, image height and width calculations can lead to divide-by-zero conditions which also lead to undefined behavior. This flaw can be triggered by a crafted input file processed by ImageMagick and could impact application availability. The patch uses multiplication in addition to the function `PerceptibleReciprocal()` in order to prevent such divide-by-zero conditions. This flaw affects ImageMagick versions prior to 7.0.9-0.
Weakness: CWE-369
Which versions are affected by CVE-2020-27756?
It affects 1 product.
Products include Imagemagick Imagemagick.
How do I fix CVE-2020-27756?
Upgrade to a fixed version.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2020-27756 being exploited?
There is no known exploitation of CVE-2020-27756 in the wild and no public exploit code.
Other vulnerabilities in Imagemagick Imagemagick
Sources
Also known as DEBIAN-CVE-2020-27756, GHSA-ghpq-hg85-4p3m, JLSEC-2026-854, UBUNTU-CVE-2020-27756.