Pulse Secure VPN Arbitrary Command Execution

This module exploits a post-auth command injection in the Pulse Secure
VPN server to execute commands as root. The env(1) command is used to
bypass application whitelisting and run arbitrary commands.

Please see related module auxiliary/gather/pulse_secure_file_disclosure
for a pre-auth file read that is able to obtain plaintext and hashed
credentials, plus session IDs that may be used with this exploit.

A valid administrator session ID is required in lieu of untested SSRF.