Title

TCP Wrappers must be enabled and configured per site policy to only allow access by approved hosts and services. (Cat II impact)

Discussion

TCP Wrappers are a host-based access control system that allows administrators to control who has access to various network services based on the IP address of the remote end of the connection. TCP Wrappers also provide logging information via syslog about both successful and unsuccessful connections.

Check Content

Check that TCP Wrappers are enabled and the host.deny and host.allow files exist. # inetadm -p | grep tcp_wrappers If the output of this command is "tcp_wrappers=FALSE", this is a finding. # ls /etc/hosts.deny /etc/hosts.deny # ls /etc/hosts.allow /etc/hosts.allow If these files do not exist or do not contain the names of allowed or denied hosts, this is a finding.

Fix Text

The root role is required. To enable TCP Wrappers, run the following commands: 1. Create and customize your policy in /etc/hosts.allow: # echo "ALL: [net]/[mask], [net]/[mask], ..." > /etc/hosts.allow where each [net>/[mask> combination (for example, the Class C address block "192.168.1.0/255.255.255.0") can represent one network block in use by your organization that requires access to this system. 2. Create a default deny policy in /etc/hosts.deny: # echo "ALL: ALL" >/etc/hosts.deny 3. Enable TCP Wrappers for all services started by inetd: # inetadm -M tcp_wrappers=TRUE The versions of SunSSH (0.5.11) and sendmail that ship with Solaris 11 will automatically use TCP Wrappers to filter access if a hosts.allow or hosts.deny file exists. The use of OpenSSH access is controlled by the sshd_config file starting with Solaris 11.3. SunSSH is removed starting with Solaris 11.4.

Additional Identifiers

Rule ID: SV-216083r959010_rule

Vulnerability ID: V-216083

Group Title: SRG-OS-000480

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.