Insecure TLS_DH_anon_WITH_DES_CBC_SHA

IANA name:

TLS_DH_anon_WITH_DES_CBC_SHA

Hex code:

0x00, 0x1A

TLS Version(s):

TLS1.0, TLS1.1, TLS1.2, TLS1.3

Protocol:

Transport Layer Security (TLS)

Key Exchange:

Diffie-Hellman (DH)

Non-ephemeral Key Exchange:

This key exchange algorithm does not support Perfect Forward Secrecy (PFS) which is recommended, so attackers cannot decrypt the complete communication stream.

Raccoon Attack:

The so-called Raccoon Attack affects the specifications of TLS 1.2 and below when using a DH(E) key exchange. According to the researchers, while very hard to exploit, in rare circumstances this timing attack allows attackers to decrypt the connection between users and the server. A fix has been introduced in the TLS 1.3 specification.

Authentication:

Anonymous (anon)

Anonymous key exchange:

Anonymous key exchanges are generally vulnerable to Man in the Middle attacks.

Encryption:

Data Encryption Standard with 56bit key in Cipher Block Chaining mode (DES CBC)

Cipher Block Chaining:

In 2013, researchers demonstrated a timing attack against several TLS implementations using the CBC encryption algorithm (see isg.rhul.ac.uk). Additionally, the CBC mode is vulnerable to plain-text attacks in TLS 1.0, SSL 3.0 and lower. A fix has been introduced with TLS 1.2 in form of the GCM mode which is not vulnerable to the BEAST attack. GCM should be preferred over CBC.

Data Encryption Standard:

DES is considered weak, primarily due to its short key-lengths of 40 or 65-Bit. Furthermore, it has been withdrawn as a standard by the National Institute of Standards and Technology in 2005.

Hash:

HMAC Secure Hash Algorithm 1 (SHA)

Secure Hash Algorithm 1:

The Secure Hash Algorithm 1 has been proven to be insecure as of 2017 (see shattered.io).

Included in RFC:

Machine-readable:

application/json