Describe CVE-2021-21840.
What is CVE-2021-21840?
An exploitable integer overflow vulnerability exists within the MPEG-4 decoding functionality of the GPAC Project on Advanced Content library v1.0.1. A specially crafted MPEG-4 input used to process an atom using the “saio” FOURCC code cause an integer overflow due to unchecked arithmetic resulting in a heap-based buffer overflow that causes memory corruption. An attacker can convince a user to open a video to trigger this vulnerability..