CVE-2005-2643: Tor

Medium severity, CVSS 5.0. EPSS: 1.2% chance of exploitation in the next 30 days.

Tor 0.1.0.13 and earlier, and experimental versions 0.1.1.4-alpha and earlier, does not reject certain weak keys when using ephemeral Diffie-Hellman (DH) handshakes, which allows malicious Tor servers to obtain the keys that a client uses for other systems in the circuit.

Affected products

• Tor Tor: version 0.0.9 only; version 0.0.9.1 only; version 0.0.9.2 only; version 0.0.9.3 only; version 0.0.9.4 only; version 0.0.9.5 only; …

Published 2005-08-23. Last modified 2026-06-16.