5.3.14 Ensure SSH PermitUserEnvironment is disabled

Information

The PermitUserEnvironment option allows users to present environment options to the ssh daemon.

Rationale:

Permitting users the ability to set environment variables through the SSH daemon could potentially allow users to bypass security controls (e.g. setting an execution path that has ssh executing a Trojan's programs)

Solution

Edit the /etc/ssh/sshd_config file to set the parameter as follows:

PermitUserEnvironment no

Default Value:

PermitUserEnvironment no

See Also

https://workbench.cisecurity.org/files/3636