The stable-diffusion.cpp library, used for diffusion model inference, contained a heap buffer overflow in its pickle .ckpt file parser within src/model.cpp. Specifically, the GLOBAL opcode handler failed to validate newline-delimited fields properly, allowing a crafted .ckpt file lacking expected newlines to cause the parser to use an invalid copy length (-1), resulting in heap corruption. This vulnerability affects versions prior to master-584-0a7ae07. Exploitation requires user interaction to load a malicious .ckpt file from an untrusted source. The issue is resolved in version master-584-0a7ae07.

Successful exploitation can lead to heap corruption, potentially allowing an attacker to execute arbitrary code, cause denial of service, or compromise confidentiality and integrity of the affected system. The vulnerability requires loading a malicious .ckpt file, so the attack vector is limited to scenarios where untrusted model files are loaded.

A fix is available in stable-diffusion.cpp version master-584-0a7ae07. Users and developers should update to this version to remediate the vulnerability. If immediate updating is not possible, avoid loading .ckpt checkpoint files from untrusted sources and prefer trusted model sources and safer formats such as .safetensors.