stb_image.h (aka the stb image loader) 2.19, as used in libsixel and other products, has a reachable assertion in stbi__create_png_image_raw.
The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Libsixel | Libsixel_project | 2.19 (including) | 2.19 (including) |
| Libstb | Ubuntu | impish | * |
| Libstb | Ubuntu | kinetic | * |
| Libstb | Ubuntu | lunar | * |
| Libstb | Ubuntu | mantic | * |
| Libstb | Ubuntu | trusty | * |
| Libstb | Ubuntu | xenial | * |
While assertion is good for catching logic errors and reducing the chances of reaching more serious vulnerability conditions, it can still lead to a denial of service. For example, if a server handles multiple simultaneous connections, and an assert() occurs in one single connection that causes all other connections to be dropped, this is a reachable assertion that leads to a denial of service.