The SSH client must be configured to not use Cipher-Block Chaining (CBC)-based ciphers.

From Red Hat Enterprise Linux 5 Security Technical Implementation Guide

Associated with IA controls: ECSC-1

Associated with: CCI-000366

SV-37830r1_rule The SSH client must be configured to not use Cipher-Block Chaining (CBC)-based ciphers.

Vulnerability discussion

The (CBC) mode of encryption as implemented in the SSHv2 protocol is vulnerable to chosen-plaintext attacks and must not be used.

Check content

Fix text

Edit the SSH client configuration and remove any ciphers not starting with "3des" or "aes" and remove any ciphers ending with "cbc". If necessary, add a "Ciphers" line.

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