Tag Archives: aws

A Quick AWS Lambda Reverse Shell

Let’s say you’re doing a pentest, and you run across access to AWS Lambda. I recently learned you can get a persistent shell (for 15 minutes, at least) via Lambda, which seemed odd to me because always just considered Lambda a repeatable, but ephemeral thing.

Anyway, first create lambda_function.py with the following code. Note that you’ll need a hostname to connect to. In my case, I used pizzapower.me.

Lambda reverse shell python code.

Next, zip this up into shell.zip.

Creating shell.zip that contains our reverse shell function.

Now we are going to create a Lambda function and upload our shell.zip with the following command

aws lambda create-function --function-name test --runtime python3.9 --handler lambda_function.lambda_handler --timeout 900 --zip-file fileb://shell.zip --role <The Amazon Resource Name (ARN) of the function's execution role>
Creating our function and uploading the code.

Don’t forget to start your listener, and when you are ready, trigger the function!

And catch the shell.

According to the docs, “a Lambda function always runs inside a VPC owned by the Lambda service.” But you can attach your function to your own VPC, so depending on how the victim’s AWS environment is configured, you may be able to pivot around and exploit some more stuff.