The gdImageCreateFromGd2Ctx function in gd_gd2.c in the GD Graphics Library (aka libgd) before 2.2.4 allows remote attackers to cause a denial of service (application crash) via a crafted image file.
http://libgd.github.io/release-2.2.4.html
https://access.redhat.com/errata/RHSA-2017:3221
https://access.redhat.com/errata/RHSA-2018:1296
https://github.com/libgd/libgd/commit/fe9ed49dafa993e3af96b6a5a589efeea9bfb36f
https://www.tenable.com/security/tns-2017-04
http://www.debian.org/security/2017/dsa-3777
http://www.openwall.com/lists/oss-security/2017/01/26/1