3DES vulnerability for 5061 port

Question

How can I solve "64-bit block cipher 3DES vulnerable to SWEET32 attack" and "Key exchange (dh 1024) of lower strength than certificate key" problems for 5061 port on centOS7?

PORT     STATE SERVICE
5061/tcp open  sip-tls
| ssl-enum-ciphers:
|   TLSv1.2:
|     ciphers:
|       TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA (dh 1024) - D
|       TLS_DHE_RSA_WITH_AES_128_CBC_SHA (dh 1024) - A
|       TLS_DHE_RSA_WITH_AES_128_CBC_SHA256 (dh 1024) - A
|       TLS_DHE_RSA_WITH_AES_128_GCM_SHA256 (dh 1024) - A
|       TLS_DHE_RSA_WITH_AES_256_CBC_SHA (dh 1024) - A
|       TLS_DHE_RSA_WITH_AES_256_CBC_SHA256 (dh 1024) - A
|       TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 (dh 1024) - A
|       TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA (secp256r1) - C
|       TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA (secp256r1) - A
|       TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 (secp256r1) - A
|       TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (secp256r1) - A
|       TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA (secp256r1) - A
|       TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 (secp256r1) - A
|       TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (secp256r1) - A
|       TLS_RSA_WITH_3DES_EDE_CBC_SHA (rsa 2048) - C
|       TLS_RSA_WITH_AES_128_CBC_SHA (rsa 2048) - A
|       TLS_RSA_WITH_AES_128_CBC_SHA256 (rsa 2048) - A
|       TLS_RSA_WITH_AES_128_GCM_SHA256 (rsa 2048) - A
|       TLS_RSA_WITH_AES_256_CBC_SHA (rsa 2048) - A
|       TLS_RSA_WITH_AES_256_CBC_SHA256 (rsa 2048) - A
|       TLS_RSA_WITH_AES_256_GCM_SHA384 (rsa 2048) - A
|     compressors:
|       NULL
|     cipher preference: client
|     warnings:
|       64-bit block cipher 3DES vulnerable to SWEET32 attack
|       Key exchange (dh 1024) of lower strength than certificate key
|_  least strength: D

AymericM AymericM · Accepted Answer · 2020-10-26T13:19:12

I guess you are asking a question as an administrator of a sip service.

You should offer a different cipher suite and configure it based on your security requirements.

This is an example of cipher suite for a pretty strong service:

cipher_list = HIGH:!COMPLEMENTOFDEFAULT:!kRSA:!PSK:!SRP

If you wish to keep your current cipher suite and just remove 3DES, you can do so by only disabling 3DES

cipher_list = YOURCURRENTCIPHERSUITE:!3DES

Example above, of course, are showing typical configuration when openssl is used. You need to adapt them if you are using another system.

You should also have some way to set a DH PARAMETER in your configuration and you need to configure it to a higher number of bits. For example:

$> openssl dhparam -out dhparam.pem 3072

The result would be this one:

PORT     STATE SERVICE
5061/tcp open  sip-tls
| ssl-enum-ciphers:
|   TLSv1.2:
|     ciphers:
|       TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (secp256r1) - A
|       TLS_DHE_RSA_WITH_AES_256_GCM_SHA384 (dh 3072) - A
|       TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256 (secp256r1) - A
|       TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256 (dh 3072) - A
|       TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (secp256r1) - A
|       TLS_DHE_RSA_WITH_AES_128_GCM_SHA256 (dh 3072) - A
|       TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 (secp256r1) - A
|       TLS_DHE_RSA_WITH_AES_256_CBC_SHA256 (dh 3072) - A
|       TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 (secp256r1) - A
|       TLS_DHE_RSA_WITH_AES_128_CBC_SHA256 (dh 3072) - A
|       TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA (secp256r1) - A
|       TLS_DHE_RSA_WITH_AES_256_CBC_SHA (dh 3072) - A
|       TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA (secp256r1) - A
|       TLS_DHE_RSA_WITH_AES_128_CBC_SHA (dh 3072) - A
|     compressors:
|       NULL
|     cipher preference: server
|_  least strength: A

3DES vulnerability for 5061 port

1 Answers