tif_getimage.c in LibTIFF through 4.0.10, as used in GDAL through 3.0.1 and other products, has an integer overflow that potentially causes a heap-based buffer overflow via a crafted RGBA image, related to a "Negative-size-param" condition.
https://www.debian.org/security/2020/dsa-4670
https://www.debian.org/security/2020/dsa-4608
https://security.gentoo.org/glsa/202003-25
https://seclists.org/bugtraq/2020/Jan/32
https://lists.debian.org/debian-lts-announce/2020/03/msg00020.html
https://lists.debian.org/debian-lts-announce/2019/11/msg00027.html
https://gitlab.com/libtiff/libtiff/commit/4bb584a35f87af42d6cf09d15e9ce8909a839145
https://github.com/OSGeo/gdal/commit/21674033ee246f698887604c7af7ba1962a40ddf