An issue was discovered in Deserializer::read_vec in the cdr crate before 0.2.4 for Rust. A user-provided Read implementation can gain access to the old contents of newly allocated heap memory, violating soundness.

Affected: crates.io: cdr

An issue was discovered in Deserializer::read_vec in the cdr crate before 0.2.4 for Rust. A user-provided Read implementation can gain access to the old contents of newly allocated heap memory, violating soundness.

Affected: crates.io: cdr

`Deserializer::read_vec()` created an uninitialized buffer and passes it to a user-provided `Read` implementation (`Deserializer.reader.read_exact()`).

Passing an uninitialized buffer to an arbitrary `Read` implementation is currently defined as undefined behavior in Rust. Official documentation for the `Read` trait explains the following: "It is your responsibility to make sure that buf is initialized before calling read. Calling read with an uninitialized buf (of the kind one obtains via MaybeUninit<T>) is not safe, and can lead to undefined behavior."

The flaw was corrected in commit ce310f7 by zero-initializing the newly allocated buffer before handing it to `Deserializer.reader.read_exact()`.