Advisories for Cargo/Xcb package

The API of xcb::Connection has constructors which allow an arbitrary RawFd to be used as a socket connection. On either failure of these constructors or on the drop of Connection, it closes the associated file descriptor. Thus, a program which uses an OwnedFd (such as a UnixStream) as the file descriptor can close the file descriptor and continue to attempt using it or close an already-closed file descriptor, violating I/O …

An issue was discovered in the xcb crate through 2021-02-04 for Rust. It has a soundness violation because transmutation to the wrong type can happen after xcb::base::cast_event uses std::mem::transmute to return a reference to an arbitrary type.

An issue was discovered in the xcb crate through 2021-02-04 for Rust. It has a soundness violation because xcb::xproto::GetAtomNameReply::name() calls std::str::from_utf8_unchecked() on unvalidated bytes from an X server.

An issue was discovered in the xcb crate through 2021-02-04 for Rust. It has a soundness violation because there is an out-of-bounds read in xcb::xproto::change_property(), as demonstrated by a format=32 T=u8 situation where out-of-bounds bytes are sent to an X server.

An issue was discovered in the xcb crate through 2020-12-10 for Rust. base::Error does not have soundness. Because of the public ptr field, a use-after-free or double-free can occur.

The function xcb::xproto::GetPropertyReply::value() returns a slice of type T where T is an unconstrained type parameter. The raw bytes received from the X11 server are interpreted as the requested type. The users of the xcb crate are advised to only call this function with the intended types. These are u8, u16, and u32. This issue is tracked here: https://github.com/rust-x-bindings/rust-xcb/issues/95