Affected versions of this crate unconditionally implemented Send/Sync for QueueSender<T>, allowing to send non-Send T to other threads by invoking (&QueueSender<T>).send().

This fails to prevent users from creating data races by sending types like Rc<T> or Arc<Cell<T>> to other threads, which can lead to memory corruption. The flaw was corrected in commit 1e462c3 by imposing T: Send to both Send/Sync impls for QueueSender<T>/QueueReceiver<T>.

References

• https://nvd.nist.gov/vuln/detail/CVE-2020-36437
• https://rustsec.org/advisories/RUSTSEC-2020-0117.html
• https://raw.githubusercontent.com/rustsec/advisory-db/main/crates/conqueue/RUSTSEC-2020-0117.md
• longshorej/conqueue@1e462c3