A crafted JPEG image may lead the JPEG reader to underflow its data pointer, allowing user-controlled data to be written in heap. To a successful to be performed the attacker needs to perform some triage over the heap layout and craft an image with a malicious format and payload. This vulnerability can lead to data corruption and eventual code execution or secure boot circumvention. This flaw affects grub2 versions prior grub-2.12.
Exploitability
AV:LAC:HPR:LUI:NScope
S:UImpact
C:HI:HA:H7/CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:HMemory Safety