WAF Bypass Tool – A Comprehensive Guide To Enhancing Web Application Security

WAF bypass Tool is an open source tool to analyze the security of any WAF for False Positives and False Negatives using predefined and customizable payloads.

Check your WAF before an attacker does. WAF Bypass Tool is developed by Nemesida WAF team with the participation of community.

How To Run

Run Using Docker

The latest waf-bypass always available via the Docker Hub. It can be easily pulled via the following command:

# docker pull nemesida/waf-bypass
# docker run nemesida/waf-bypass --host='example.com'

Run using pipx

# pipx install git+https://github.com/nemesida-waf/waf-bypass.git
# <pipx bin dir>/waf-bypass

Run directly from source code using CLI

# git clone https://github.com/nemesida-waf/waf_bypass.git /opt/waf-bypass/
# python3 -m pip install -r /opt/waf-bypass/requirements.txt
# python3 /opt/waf-bypass/main.py --host='example.com'

Options

• '--proxy' (--proxy='http://proxy.example.com:3128') – option allows to specify where to connect to instead of the host.
• '--header' (--header 'Authorization: Basic YWRtaW46YWRtaW4=' --header 'X-TOKEN: ABCDEF') – option allows to specify the HTTP header to send with all requests (e.g. for authentication). Multiple use is allowed.
• '--user-agent' (--user-agent 'MyUserAgent 1/1') – option allows to specify the HTTP User-Agent to send with all requests, except when the User-Agent is set by the payload ("USER-AGENT").
• '--block-code' (--block-code='403' --block-code='222') – option allows you to specify the HTTP status code to expect when the WAF is blocked. (default is 403). Multiple use is allowed.
• '--threads' (--threads=15) – option allows to specify the number of parallel scan threads (default is 10).
• '--timeout' (--timeout=10) – option allows to specify a request processing timeout in sec. (default is 30).
• '--exclude-dir' – exclude the payload’s directory (--exclude-dir='SQLi,XSS').
• '--json-format' – an option that allows you to display the result of the work in JSON format (useful for integrating the tool with security platforms). If the option is not specified, the output will be in table format (the default format).
• '--details' – display the False Positive and False Negative payloads. Not compatible with option --json-format option.
• '--curl-replay' – display the cURL command to reproduce False Positive, False Negative or Failed requests. Not compatible with option --json-format option.

JSON Format

JSON output specification example:

{
  "TARGET": "https://example.com", // defined by --host option
  "PROXY": {},                     // defined by --proxy option
  "HEADERS": {                     // defined by --header option
    "User-Agent": ""
  },
  "BLOCK-CODE": [                  // defined by --block-code option
    ...
  ],
  "THREADS": 50,                   // defined by --threads option
  "TIMEOUT": 30,                   // defined by --timeout option
  "EXCLUDE-DIR": [                 // defined by --exclude-dir option
    ...
  ],
  "FAILED": {                      // requests with failed processing status
    "MFD/7.json": {
      "BODY": "WBHTTPSConnectionPool(host='example.com', port=443): Read timed out. (read timeout=1)"
    },
    ...
  },
  "PASSED": {                      // passed requests
    "UWA/3.json": {
      "URL": "403 RESPONSE CODE"
    },
    ...
  },
  "FALSED": {                      // requests with false positive processing status
    ...
  },
  "BYPASSED": {                    // requests with false negative processing status
    "UWA/26.json": {
      "URL": "200 RESPONSE CODE"
    },
    ...
  },
  "TestRequest": {                // test requests with processing status, exclude passed
    "FAILED": {},
    "FALSED": {
        "UWA/3.json": {
        "URL": "403 RESPONSE CODE"
        },
        ...
    }
    
  },
  "CURL": {                       // cURL command to reproduce false positive and false negative requests
    "FALSED": {},
    "BYPASSED": {
      "UWA/26.json": {
        "URL": "curl -X GET -H 'Accept: */*' -H 'Accept-Encoding: gzip, deflate' -H 'Connection: keep-alive' -H 'User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/108.0.0.0 Safari/537.36' 'https://example.com/do.php#.png'"
      },
      ...
    }
  }

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