Providing DevOps and security teams script to identify cloud workloads that may be vulnerable to the Log4j vulnerability(CVE-2021-44228) in their AWS account.

Introduction

we are providing DevOps and security teams script to identify cloud workloads that may be vulnerable to the Log4j vulnerability(log4shell) in their AWS account. The script enables security teams to identify external-facing AWS assets by running the exploit on them, and thus be able to map them and quickly patch them

General Information

• Information about CVE-2021-44228: https://nvd.nist.gov/vuln/detail/CVE-2021-44228
• central updated location which outlines everything you need to know about Log4Shell: https://www.mitiga.io/blog/log4shell-everything-in-one-place
• Algorithm drill-down: https://www.mitiga.io/blog/log4shell-identify-vulnerable-external-facing-workloads-in-aws-tutorial

Features

• Scans the resources in all regions
• Scans all the compute resources which exposed to the internet
• Ability to execute it with a proxy
• Supporting multiple ways to configure the AWS credentials using AWS known environment variables: https://docs.aws.amazon.com/cli/latest/userguide/cli-configure-envvars.html

Installation / Requirements

• cPython 3.6 and higher

• install the required Python packages:

  pip3 install -r requirements.txt

• AWS permissions to scans the resources:

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "ec2:DescribeInstances",
                "ec2:DescribeSecurityGroups",
                "elasticloadbalancing:DescribeLoadBalancers",
                "elasticloadbalancing:DescribeListeners",
                "elasticloadbalancing:DescribeRules",
                "elasticloadbalancing:DescribeTargetGroupAttributes",
                "elasticloadbalancing:DescribeTargetGroups",
            ],
            "Resource": "*"
        }
    ]
}

Before Execution The Script

You need a server which will wait for DNS requests from the vulnerable endpoints, For this demo we are using: interactsh, which is an external tool You can use interactsh client or Interactsh web app

Executing

1. Get the URL address for the DNS requests. Using 'interactsh' you can find it in the client app here:

   

   or using the web app:

   

2. Execute the main.py script with argument: '--dest-domain' and (optional)'--proxies'. examples:

   python3 main.py --dest-domain test.interactsh.com
   python3 main.py --dest-domain test2.interactsh.com --proxies http://127.0.0.1:8080 https://127.0.0.1:8080

Finding Vulnerable Endpoints

the vulnerable endpoints should send DNS requests to your server with the format:

• EC2 instances: '{instance id}.{destination domain}'. example: i-092ed1f7d1230bb9a.test.interactsh.com
• Load Balancers: '{load balancer name}.{destination domain}'. example: lb-name.test.interactsh.com

cli example:

web example:

Disclaimer

This project should be used only for educational purposes. The project does not replace a mature remediation plan and does not provide full coverage on external-facing or vulnerable assets. Mitiga does not hold responsibility for any damage caused by using this project.