5.2.6 Ensure SSH Protocol is set to 2

Information

Older versions of SSH support two different and incompatible protocols: SSH1 and SSH2. SSH1 was the original protocol and was subject to security issues. SSH2 is more advanced and secure.

Rationale:

SSH v1 suffers from insecurities that do not affect SSH v2.

Solution

Edit the /etc/ssh/sshd_config file to set the parameter as follows:
Example: vim /etc/ssh/sshd_config

Protocol 2

Notes:

This command not longer exists in newer versions of SSH. This check is still being included for systems that may be running an older version of SSH. As of openSSH version 7.4 this parameter will not cause an issue when included.

This Benchmark recommendation maps to:

Red Hat Enterprise Linux 7 Security Technical Implementation Guide:

Version 2, Release: 3 Benchmark Date: 26 Apr 2019



Vul ID: V-72251

Rule ID: SV-86875r4_rule

STIG ID: RHEL-07-040390

Severity: CAT I

See Also

https://workbench.cisecurity.org/files/2688

Item Details

Category: SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|SC-8, CSCv7|14.4

Plugin: Unix

Control ID: 6df35a905066b66e0a1795268fae0c6685333e3345ec88ce0c6330762dce2236