RHEL 9 SSH daemon must not allow compression or must only allow compression after successful authentication.
An XCCDF Rule
Description
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.
- ID
- SV-258002r991589_rule
- Version
- RHEL-09-255130
- Severity
- Medium
- References
- Updated
Remediation Templates
A Manual Procedure
Configure the SSH daemon to not allow compression.
Uncomment the "Compression" keyword in "/etc/ssh/sshd_config" on the system and set the value to "delayed" or "no":
Compression no