Add PoC exploit for CVE-2018-15961

[postmodern]

Add a PoC exploit for CVE-2018-15961, arbitrary file upload that code lead to code execution in ColdFusion versions July 12 release (2018.0.0.310739), Update 6 and earlier, and Update 14 and earlier.

Reference PoCs

• https://github.com/bu1xuan2/CVE-2018-15961/blob/main/CVE-2018-15961.py (with JSP reverse shell payload)
• https://github.com/orangmuda/CVE-2018-15961/blob/main/exploit.py
• https://github.com/xbufu/CVE-2018-15961/blob/main/coldfusion_rce.py

Vuln App

• https://github.com/vulhub/vulhub/tree/639e32be6c0425b11d7d56594761c5e599a6a9d5/base/coldfusion/11u3 (?)
• https://github.com/vulhub/vulhub/tree/639e32be6c0425b11d7d56594761c5e599a6a9d5/coldfusion/CVE-2017-3066 (might also be vulnerable?)

How to Submit a PoC

See the CONTRIBUTING file for instructions on how to submit a PoC exploit.

[postmodern]

This requires Ronin::Support::Network::HTTP supporting multi-part file uploads. ronin-rb/ronin-support#504.