An issue was discovered in the image crate before 0.21.3 for Rust, affecting the HDR image format decoder. Vec::set_len is called on an uninitialized vector, leading to a use-after-free and arbitrary code execution.

Affected: crates.io: image

Affected versions of this crate would call Vec::set_len on an uninitialized vector with user-provided type parameter, in an interface of the HDR image format decoder. They would then also call other code that could panic before initializing all instances.

This could run Drop implementations on uninitialized types, equivalent to use-after-free, and allow an attacker arbitrary code execution.

Two different fixes were applied. It is possible to conserve the interface by ensuring proper initialization before calling Vec::set_len. Drop is no longer called in case of panic, though.

Starting from version 0.22, a breaking change to the interface requires callers to pre-allocate the output buffer and pass a mutable slice instead, avoiding all unsafe code.

Affected: crates.io: image

Affected versions of this crate would call `Vec::set_len` on an uninitialized vector with user-provided type parameter, in an interface of the HDR image format decoder. They would then also call other code that could panic before initializing all instances.

This could run Drop implementations on uninitialized types, equivalent to use-after-free, and allow an attacker arbitrary code execution.

Two different fixes were applied. It is possible to conserve the interface by ensuring proper initialization before calling `Vec::set_len`. Drop is no longer called in case of panic, though.

Starting from version `0.22`, a breaking change to the interface requires callers to pre-allocate the output buffer and pass a mutable slice instead, avoiding all unsafe code.