The design objective of the Command Line Parser is used to parse the command line arguments. The parser parsing a string and returns an object representing the values extracted. This is the the regular expression design objective. The Cisco IOS XE is a train of Cisco Systems’ widely deployed Internetworking Operating System (IOS), introduced with the ASR 1000 series. IOS XE is a combination of a linux kernel and a (monolithic) application (IOSd) that runs on top of this kernel. The goal of IOS SE aim to integrate the IOS feature set for routing and switching cope with modern business critical applications. Vulnerability found daily we have not surprise. A CLI command injection vulnerability has been found on CISCO IOS XE this month. For more details, please find below url for reference.