Snow Crate Nonce Increment Vulnerability in Rust

A denial-of-service vulnerability has been identified in the Snow crate for Rust, affecting versions prior to 0.9.5. The issue arises when stateful TransportState is used, allowing unauthenticated payloads to increment a nonce in Snow's internal state. This creates a mismatch in expected nonce values, disrupting message delivery. The vulnerability can be exploited by injecting packets into the channel over which the Noise session operates.

Impact

Exploitation of this vulnerability causes a denial-of-service condition by disrupting message delivery, with the sending and receiving sides expecting different nonce values.

Remediation

Users are advised to update to Snow version 0.9.5 or later.