Gimp: gimp: heap-based buffer overflow in ico loader via integer overflow in embedded png dimensions

A flaw was found in GIMP's ICO file loader. When processing an ICO file containing an embedded PNG image, an integer overflow can occur during the calculation of the required buffer size. This leads to an undersized buffer being allocated, causing a heap-based buffer overflow when the decoded pixel data is written. A remote attacker could exploit this by crafting a malicious ICO file, which, when opened, could lead to arbitrary code execution or a crash.