RustCrypto CMOV provides conditional move CPU intrinsics which are guaranteed on major platforms to execute in constant-time and not be rewritten as branches by the compiler. Prior to 0.4.4, the thumbv6m-none-eabi (Cortex M0, M0+ and M1) compiler emits non-constant time assembly when using cmovnz (portable version). This vulnerability is fixed in 0.4.4.
Two separate operations in a product require different amounts of time to complete, in a way that is observable to an actor and reveals security-relevant information about the state of the product, such as whether a particular operation was successful or not.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Cmov | Rustcrypto | * | 0.4.4 (excluding) |