Insecure TLS_RSA_WITH_RC4_128_MD5
- IANA name:
- TLS_RSA_WITH_RC4_128_MD5
- GnuTLS name:
- TLS_RSA_ARCFOUR_128_MD5
- Hex code:
- 0x00, 0x04
- TLS Version(s):
- TLS1.0, TLS1.1, TLS1.2, TLS1.3
- Protocol:
- Transport Layer Security (TLS)
- Key Exchange:
- Rivest Shamir Adleman algorithm (RSA)
- Authentication:
- Rivest Shamir Adleman algorithm (RSA)
- Encryption:
- Rivest Cipher 4 with 128bit key (RC4 128)
- Hash:
- HMAC Message Digest 5 (MD5)
- Included in RFC:
- Machine-readable:
- application/json
This key exchange algorithm does not support Perfect Forward Secrecy (PFS) which is recommended, so attackers cannot decrypt the complete communication stream.
There are reports that servers using the RSA authentication algorithm with keys longer than 3072-bit may experience heavy performance issues leading to connection timeouts and even service unavailability if many clients open simultaneous connections.
IETF has officially prohibited RC4 for use in TLS in RFC 7465. Therefore, it can be considered insecure.
The Message Digest 5 algorithm suffers form multiple vulnerabilities and is considered insecure.