CVE-2022-50237: Medium severity Rust ed25519-dalek vulnerability
The ed25519-dalek crate before 2 for Rust allows a double public key signing function oracle attack. The Keypair implementation leads to a simple computation for extracting a private key.
Other sources
Versions of ed25519-dalek prior to v2.0 model private and public keys as separate types which can be assembled into a Keypair, and also provide APIs for serializing and deserializing 64-byte private/public keypairs.
Such APIs and serializations are inherently unsafe as the public key is one of the inputs used in the deterministic computation of the S part of the signature, but not in the R value. An adversary could somehow use the signing function as an oracle that allows arbitrary public keys as input can obtain two signatures for the same message sharing the same R and only differ on the S part.
Unfortunately, when this happens, one can easily extract the private key.
Revised public APIs in v2.0 of ed25519-dalek do NOT allow a decoupled private/public keypair as signing input, except as part of specially labeled "hazmat" APIs which are clearly labeled as being dangerous if misused.
— GitHub
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2022-50237?
CVE-2022-50237 is considered a high-severity vulnerability due to its potential to allow private key extraction through a double signing function oracle attack.
How do I fix CVE-2022-50237?
To fix CVE-2022-50237, update the ed25519-dalek crate to version 2 or later in your Rust project.
What types of applications are affected by CVE-2022-50237?
CVE-2022-50237 affects applications that use the ed25519-dalek crate for cryptographic operations involving Ed25519 keypairs.
What kind of attack does CVE-2022-50237 facilitate?
CVE-2022-50237 facilitates a double public key signing function oracle attack, enabling an adversary to extract private keys.
Is there a workaround for CVE-2022-50237 until I can update?
There are no specific workarounds for CVE-2022-50237; upgrading to the patched version is strongly recommended.