Feroxbuster – A Fast, Simple, Recursive Content Discovery Tool Written In Rust

What the heck is a ferox anyway?

Ferox is short for Ferric Oxide. Ferric Oxide, simply put, is rust. The name rustbuster was taken, so I decided on a variation.

What’s it do tho?

feroxbuster is a tool designed to perform Forced Browsing.

Forced browsing is an attack where the aim is to enumerate and access resources that are not referenced by the web application, but are still accessible by an attacker.

feroxbuster uses brute force combined with a wordlist to search for unlinked content in target directories. These resources may store sensitive information about web applications and operational systems, such as source code, credentials, internal network addressing, etc…

This attack is also known as Predictable Resource Location, File Enumeration, Directory Enumeration, and Resource Enumeration.

Installation

Download a Release

Releases for multiple architectures can be found in the Releases section. The latest release for each of the following systems can be downloaded and executed as shown below.

Linux x86

curl -sLO https://github.com/epi052/feroxbuster/releases/latest/download/x86-linux-feroxbuster.zip
unzip x86-linux-feroxbuster.zip
chmod +x ./feroxbuster
./feroxbuster -V

Linux x86_64

curl -sLO https://github.com/epi052/feroxbuster/releases/latest/download/x86_64-linux-feroxbuster.zip
unzip x86_64-linux-feroxbuster.zip
chmod +x ./feroxbuster
./feroxbuster -V

MacOS x86_64

curl -sLO https://github.com/epi052/feroxbuster/releases/latest/download/x86_64-macos-feroxbuster.zip
unzip x86_64-macos-feroxbuster.zip
chmod +x ./feroxbuster
./feroxbuster -V

Windows x86

https://github.com/epi052/feroxbuster/releases/latest/download/x86-windows-feroxbuster.exe.zip
Expand-Archive .feroxbuster.zip
.feroxbusterferoxbuster.exe -V

Windows x86_64

Invoke-WebRequest https://github.com/epi052/feroxbuster/releases/latest/download/x86_64-windows-feroxbuster.exe.zip -OutFile feroxbuster.zip
Expand-Archive .feroxbuster.zip
.feroxbusterferoxbuster.exe -V

Homebrew on MacOS and Linux

Installable by Homebrew throughout own formulas:

MacOS

brew tap tgotwig/feroxbuster
brew install feroxbuster

Linux

brew tap tgotwig/linux-feroxbuster
brew install feroxbuster

Cargo Install

feroxbuster is published on crates.io, making it easy to install if you already have rust installed on your system.

cargo install feroxbuster

apt Install

Download feroxbuster_amd64.deb from the Releases section. After that, use your favorite package manager to install the .deb.

wget -sLO https://github.com/epi052/feroxbuster/releases/latest/download/feroxbuster_amd64.deb.zip
unzip feroxbuster_amd64.deb.zip
sudo apt install ./feroxbuster_amd64.deb

AUR Install

Install feroxbuster-git on Arch Linux with your AUR helper of choice:

yay -S feroxbuster-git

Docker Install

The following steps assume you have docker installed / setup

First, clone the repository.

git clone https://github.com/epi052/feroxbuster.git
cd feroxbuster

Next, build the image.

sudo docker build -t feroxbuster .

After that, you should be able to use docker run to perform scans with feroxbuster.

Basic usage

sudo docker run --init -it feroxbuster -u http://example.com -x js,html

Piping from stdin and proxying all requests through socks5 proxy

cat targets.txt | sudo docker run --net=host --init -i feroxbuster --stdin -x js,html --proxy socks5://127.0.0.1:9050

Mount a volume to pass in ferox-config.toml

You’ve got some options available if you want to pass in a config file. ferox-buster.toml can live in multiple locations and still be valid, so it’s up to you how you’d like to pass it in. Below are a few valid examples:

sudo docker run --init -v $(pwd)/ferox-config.toml:/etc/feroxbuster/ferox-config.toml -it feroxbuster -u http://example.com

sudo docker run --init -v ~/.config/feroxbuster:/root/.config/feroxbuster -it feroxbuster -u http://example.com

Note: If you are on a SELinux enforced system, you will need to pass the :Z attribute also.

docker run --init -v (pwd)/ferox-config.toml:/etc/feroxbuster/ferox-config.toml:Z -it feroxbuster -u http://example.com

Define an alias for simplicity

alias feroxbuster="sudo docker run --init -v ~/.config/feroxbuster:/root/.config/feroxbuster -i feroxbuster"

Default Values

Configuration begins with with the following built-in default values baked into the binary:

• timeout: 7 seconds
• follow redirects: false
• wordlist: /usr/share/seclists/Discovery/Web-Content/raft-medium-directories.txt
• threads: 50
• verbosity: 0 (no logging enabled)
• statuscodes: 200 204 301 302 307 308 401 403 405
• useragent: feroxbuster/VERSION
• recursion depth: 4
• auto-filter wildcards – true
• output: stdout

ferox-config.toml

After setting built-in default values, any values defined in a ferox-config.toml config file will override the built-in defaults.

feroxbuster searches for ferox-config.toml in the following locations (in the order shown):

• /etc/feroxbuster/ (global)
• CONFIG_DIR/ferxobuster/ (per-user)
• The same directory as the feroxbuster executable (per-user)
• The user’s current working directory (per-target)

CONFIG_DIR is defined as the following:

• Linux: $XDG_CONFIG_HOME or $HOME/.config i.e. /home/bob/.config
• MacOs: $HOME/Library/Application Support i.e. /Users/bob/Library/Application Support
• Windows: {FOLDERID_RoamingAppData} i.e. C:UsersBobAppDataRoaming

If more than one valid configuration file is found, each one overwrites the values found previously.

If no configuration file is found, nothing happens at this stage.

As an example, let’s say that we prefer to use a different wordlist as our default when scanning; we can set the wordlist value in the config file to override the baked-in default.

Notes of interest:

• it’s ok to only specify values you want to change without specifying anything else
• variable names in ferox-config.toml must match their command-line counterpart

# ferox-config.toml

wordlist = "/wordlists/jhaddix/all.txt"

A pre-made configuration file with examples of all available settings can be found in ferox-config.toml.example.

# ferox-config.toml
# Example configuration for feroxbuster
#
# If you wish to provide persistent settings to feroxbuster, rename this file to ferox-config.toml and make sure
# it resides in the same directory as the feroxbuster binary.
#
# After that, uncomment any line to override the default value provided by the binary itself.
#
# Any setting used here can be overridden by the corresponding command line option/argument
#
# wordlist = "/wordlists/jhaddix/all.txt"
# statuscodes = [200, 500]
# threads = 1
# timeout = 5
# proxy = "http://127.0.0.1:8080"
# verbosity = 1
# quiet = true
# output = "/targets/ellingson_mineral_company/gibson.txt"
# useragent = "Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:47.0) Gecko/20100101 Firefox/47.0"
# redirects = true
# insecure = true
# extensions    = ["php", "html"]
# norecursion = true
# addslash = true
# stdin = true
# dontfilter = true
# depth = 1
# sizefilters = [5174]
# queries = [["name","value"], ["rick", "astley"]]

# headers can be specified on multiple lines or as an inline table
#
# inline example
# headers = {"stuff" = "things"}
#
# multi-line example
#   note: if multi-line is used, all key/value pairs under it belong to the headers table until the next table
#         is found or the end of the file is reached
#
# [headers]
# stuff = "things"
# more = "headers"

Command Line Parsing

Finally, after parsing the available config file, any options/arguments given on the commandline will override any values that were set as a built-in or config-file value.

USAGE:
    feroxbuster [FLAGS] [OPTIONS] --url <URL>...

FLAGS:
    -f, --addslash       Append / to each request
    -D, --dontfilter     Don't auto-filter wildcard responses
    -h, --help           Prints help information
    -k, --insecure       Disables TLS certificate validation
    -n, --norecursion    Do not scan recursively
    -q, --quiet          Only print URLs; Don't print status codes, response size, running config, etc...
    -r, --redirects      Follow redirects
        --stdin          Read url(s) from STDIN
    -V, --version        Prints version information
    -v, --verbosity      Increase verbosity level (use -vv or more for greater effect)

OPTIONS:
    -d, --depth <RECURSION_DEPTH>           Maximum recursion depth, a depth of 0 is infinite recursion (default: 4)
    -x, --extensions <FILE_EXTENSION>...    File extension(s) to search for (ex: -x php -x pdf js)
       -H, --headers <HEADER>...               Specify HTTP headers (ex: -H Header:val 'stuff: things')
    -o, --output <FILE>                     Output file to write results to (default: stdout)
    -p, --proxy <PROXY>                     Proxy to use for requests (ex: http(s)://host:port, socks5://host:port)
    -Q, --query <QUERY>...                  Specify URL query parameters (ex: -Q token=stuff -Q secret=key)
    -S, --sizefilter <SIZE>...              Filter out messages of a particular size (ex: -S 5120 -S 4927,1970)
    -s, --statuscodes <STATUS_CODE>...      Status Codes of interest (default: 200 204 301 302 307 308 401 403 405)
    -t, --threads <THREADS>                 Number of concurrent threads (default: 50)
    -T, --timeout <SECONDS>                 Number of seconds before a request times out (default: 7)
    -u, --url <URL>...                      The target URL(s) (required, unl   ess --stdin used)
    -a, --useragent <USER_AGENT>            Sets the User-Agent (default: feroxbuster/VERSION)
    -w, --wordlist <FILE>                   Path to the wordlist

Multiple Values

Options that take multiple values are very flexible. Consider the following ways of specifying extensions:

./feroxbuster -u http://127.1 -x pdf -x js,html -x php txt json,docx

The command above adds .pdf, .js, .html, .php, .txt, .json, and .docx to each url

All of the methods above (multiple flags, space separated, comma separated, etc…) are valid and interchangeable. The same goes for urls, headers, status codes, queries, and size filters.

Include Headers

./feroxbuster -u http://127.1 -H Accept:application/json "Authorization: Bearer {token}"

IPv6, non-recursive scan with INFO-level logging enabled

./feroxbuster -u http://[::1] --norecursion -vv

Read urls from STDIN; pipe only resulting urls out to another tool

cat targets | ./feroxbuster --stdin --quiet -s 200 301 302 --redirects -x js | fff -s 200 -o js-files

Proxy traffic through Burp

./feroxbuster -u http://127.1 --insecure --proxy http://127.0.0.1:8080

Proxy traffic through a SOCKS proxy

./feroxbuster -u http://127.1 --proxy socks5://127.0.0.1:9050

Pass auth token via query parameter

./feroxbuster -u http://127.1 --query token=0123456789ABCDEF

There are quite a few similar tools for forced browsing/content discovery. Burp Suite Pro, Dirb, Dirbuster, etc… However, in my opinion, there are two that set the standard: gobuster and ffuf. Both are mature, feature-rich, and all-around incredible tools to use.

So, why would you ever want to use feroxbuster over ffuf/gobuster? In most cases, you probably won’t. ffuf in particular can do the vast majority of things that feroxbuster can, while still offering boatloads more functionality. Here are a few of the use-cases in which feroxbuster may be a better fit:

• You want a simple tool usage experience
• You want to be able to run your content discovery as part of some crazy 12 command unix pipeline extravaganza
• You want to scan through a SOCKS proxy
• You want auto-filtering of Wildcard responses by default
• You want recursion along with some other thing mentioned above (ffuf also does recursion)
• You want a configuration file option for overriding built-in default values for your scans

Of note, there’s another written-in-rust content discovery tool, rustbuster. I came across rustbuster when I was naming my tool (

). I don’t have any experience using it, but it appears to be able to do POST requests with an HTTP body, has SOCKS support, and has an 8.3 shortname scanner (in addition to vhost dns, directory, etc…). In short, it definitely looks interesting and may be what you’re looking for as it has some capability I haven’t seen in similar tools.