A heap-based buffer overflow flaw was found in libtiff in the handling of TIFF images in libtiff's TIFF2PDF tool. A specially crafted TIFF file can lead to arbitrary code execution. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.
https://bugzilla.redhat.com/show_bug.cgi?id=1932044
https://gitlab.com/libtiff/libtiff/-/merge_requests/159
https://gitlab.com/rzkn/libtiff/-/commit/7be2e452ddcf6d7abca88f41d3761e6edab72b22
https://lists.debian.org/debian-lts-announce/2021/06/msg00023.html
https://security.gentoo.org/glsa/202104-06