Insecure Cipher Suite
- IANA name:
- OpenSSL name:
- GnuTLS name:
- Hex code:
- 0x00, 0x6D
- TLS Version(s):
- Transport Layer Security (TLS)
- Key Exchange:
- Diffie-Hellman (DH)
- Anonymous (anon)
- Advanced Encryption Standard with 256bit key in Cipher Block Chaining mode (AES 256 CBC)
- Secure Hash Algorithm 256 (SHA256)
- Included in RFC:
Diffie-Hellman key exchanges not using ephemeral keys do not support Perfect Forward Secrecy (PFS) which is recommended, so attackers cannot decrypt the whole communication stream.
Anonymous key exchanges are generally vulnerable to Man in the Middle attacks.
The CBC mode is vulnerable to plain-text attacks with TLS 1.0, SSL 3.0 and lower. However a real fix is implemented with TLS 1.2 in which the GCM mode was introduced and which is not vulnerable to the BEAST attack. GCM should be preferred over CBC (cf. BEAST).