Title

The SSH daemon must be configured to only use the SSHv2 protocol. (Cat I impact)

Discussion

SSHv1 is not a DoD-approved protocol and has many well-known vulnerability exploits. Exploits of the SSH daemon could provide immediate root access to the system.

Check Content

Check the SSH daemon configuration. Note that keywords are case-insensitive and arguments (args) are case-sensitive. keyword=Protocol Required arg(s)=2 Default arg values include: "2,1" Note: When the default "arg" value exactly matches the required "arg" value (see above), the <keyword=arg> are not required to exist (commented or uncommented) in the ssh (client) or sshd (server) configuration file. While not required, it is recommended that the configuration file(s) be populated with all keywords and assigned arg values as a means to explicitly document the ssh(d) binary's expected behavior. Examine the file. # cat /opt/ssh/etc/sshd_config | tr '\011' ' ' | tr -s ' ' | sed -e 's/^[ \t]*//' | grep -v '^#' | grep -i "Protocol" | cut -f 2,2 -d " " If the return value is "1" or "2,1" (double quotes are for emphasis only) , this is a finding.

Fix Text

Edit the configuration file and modify the Protocol line entry to appear as follows: Protocol 2

Additional Identifiers

Rule ID: SV-35209r1_rule

Vulnerability ID: V-4295

Group Title: GEN005500

Expert Comments

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