This is code from the following article, which describes the Heartbleed vulnerability in detail and shows how to create a demonstration.

https://www.synopsys.com/blogs/software-security/heartbleed-vulnerability-appsec-deep-dive/

You'll need a Linux computer with Docker installed.

$ git clone https://github.com/jknudsen-synopsys/heartbleed-box
$ cd heartbleed-box
$ ./build.sh
$ ./run.sh

Then open a new terminal window or tab.

$ ./simulate-post.sh username password
$ python3 exploit.py