The SSH daemon must limit connections to a single session.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-22482	GEN005533	SV-26776r1_rule	ECSC-1	Low

Description
The SSH protocol has the ability to provide multiple sessions over a single connection without reauthentication. A compromised client could use this feature to establish additional sessions to a system without consent or knowledge of the user. Alternate per-connection session limits may be documented if needed for a valid mission requirement. Greater limits are expected to be necessary in situations where TCP or X11 forwarding are used.

Description

The SSH protocol has the ability to provide multiple sessions over a single connection without reauthentication. A compromised client could use this feature to establish additional sessions to a system without consent or knowledge of the user. Alternate per-connection session limits may be documented if needed for a valid mission requirement. Greater limits are expected to be necessary in situations where TCP or X11 forwarding are used.

STIG	Date
UNIX SRG	2013-03-26

Details

Check Text ( C-27784r1_chk )
Check the SSH daemon configuration for the MaxSessions setting. # grep -i MaxSessions /etc/ssh/sshd_config \| grep -v '^#' If the setting is not present, or not set to 1, this is a finding.

Fix Text (F-24026r1_fix)
Edit the SSH daemon configuration and add or edit the MaxSessions setting value to 1.