Check: RHEL-08-010510
Red Hat Enterprise Linux 8 STIG:
RHEL-08-010510
(in versions v1 r7 through v1 r3)
Title
The RHEL 8 SSH daemon must not allow compression or must only allow compression after successful authentication. (Cat II impact)
Discussion
If compression is allowed in an SSH connection prior to authentication, vulnerabilities in the compression software could result in compromise of the system from an unauthenticated connection, potentially with root privileges.
Check Content
Verify the SSH daemon performs compression after a user successfully authenticates with the following command: $ sudo grep -i compression /etc/ssh/sshd_config Compression delayed If the "Compression" keyword is set to "yes", is missing, or the returned line is commented out, this is a finding.
Fix Text
Uncomment the "Compression" keyword in "/etc/ssh/sshd_config" (this file may be named differently or be in a different location if using a version of SSH that is provided by a third-party vendor) on the system and set the value to "delayed" or "no": Compression no The SSH service must be restarted for changes to take effect.
Additional Identifiers
Rule ID: SV-230289r743954_rule
Vulnerability ID: V-230289
Group Title: SRG-OS-000480-GPOS-00227
Expert Comments
CCIs
Number | Definition |
---|---|
CCI-000366 |
The organization implements the security configuration settings. |
Controls
Number | Title |
---|---|
CM-6 |
Configuration Settings |