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Network

Network Requests

Nuclei can act as an automatable Netcat, allowing users to send bytes across the wire and receive them, while providing matching and extracting capabilities on the response.

Network Requests start with a network block which specifies the start of the requests for the template.

# Start the requests for the template right here
network:

Inputs

First thing in the request is inputs. Inputs are the data that will be sent to the server, and optionally any data to read from the server.

At it's most simple, just specify a string, and it will be sent across the network socket.

# inputs is the list of inputs to send to the server
inputs: 
  - data: "TEST\r\n"

You can also send hex encoded text that will be first decoded and the raw bytes will be sent to the server.

inputs:
  - data: "50494e47"
    type: hex
  - data: "\r\n"

Helper function expressions can also be defined in input and will be first evaluated and then sent to the server. The last Hex Encoded example can be sent with helper functions this way -

inputs:
  - data: 'hex_decode("50494e47")\r\n'

One last thing that can be done with inputs is reading data from the socket. Specifying read-size with a non-zero value will do the trick. You can also assign the read data some name, so matching can be done on that part.

inputs:
  - read-size: 8

Example with reading a number of bytes, and only matching on them.

inputs:
  - read-size: 8
    name: prefix
...
matchers:
  - type: word
    part: prefix
    words: 
      - "CAFEBABE"

Multiple steps can be chained together in sequence to do network reading / writing.

Host

The next part of the requests is the host to connect to. Dynamic variables can be placed in the path to modify its value on runtime. Variables start with {{ and end with }} and are case-sensitive.

  1. Hostname - variable is replaced by the hostname provided on command line.

An example name value:

host: 
  - "{{Hostname}}"

Nuclei can also do TLS connection to the target server. Just add tls:// as prefix before the Hostname and you're good to go.

host:
  - "tls://{{Hostname}}"

If a port is specified in the host, the user supplied port is ignored and the template port takes precedence.

Matchers / Extractor Parts

Valid part values supported by Network protocol for Matchers / Extractor are -

Value Description
request Network Request
data Final Data Read From Network Socket
raw / body / all All Data received from Socket

Example Network Template

The final example template file for a hex encoded input to detect MongoDB running on servers with working matchers is provided below.

id: input-expressions-mongodb-detect

info:
  name: Input Expression MongoDB Detection
  author: pd-team
  severity: info
  reference: https://github.com/orleven/Tentacle

network:
  - inputs:
      - data: "{{hex_decode('3a000000a741000000000000d40700000000000061646d696e2e24636d640000000000ffffffff130000001069736d6173746572000100000000')}}"
    host:
      - "{{Hostname}}"
    read-size: 2048
    matchers:
      - type: word
        words:
          - "logicalSessionTimeout"
          - "localTime"

More complete examples are provided here