Parsec is a cloud-based application for cryptographically secure file sharing. In versions on the 3.x branch prior to 3.6.0, `libparsec_crypto`, a component of the Parsec application, does not check for weak order point of Curve25519 when compiled with its RustCrypto backend. In practice this means an attacker in a man-in-the-middle position would be able to provide weak order points to both parties in the Diffie-Hellman exchange, resulting in a high probability to for both parties to obtain the same shared key (hence leading to a successful SAS code exchange, misleading both parties into thinking no MITM has occurred) which is also known by the attacker. Note only Parsec web is impacted (as Parsec desktop uses `libparsec_crypto` with the libsodium backend). Version 3.6.0 of Parsec patches the issue.
CVSS 3.x
| Source | Score | Severity | Vector | Exploitability | Impact |
|---|---|---|---|---|---|
| security-advisories@github.com | 8.3 | HIGH | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L | 2.8 | 5.5 |
Products Affected
| Vendor | Product | Version |
|---|---|---|
| parsec.cloud | parsec | * |