A little bird told me my original quills store was vulnerable to illegal hacking! I’ve fixed my store now though, and now it should be impossible to hack!

Source

Author: JoshDaBosh

Source:

require 'sinatra'
require 'sqlite3'

set :server, :puma
set :bind, "0.0.0.0"
set :port, 4567
set :environment, :production

get '/' do
    db = SQLite3::Database.new "quills.db"
    @row = db.execute( "select * from quills" )
    

    erb :index
end

get '/quills' do
    erb :quills 

end


post '/quills' do
    db = SQLite3::Database.new "quills.db"
    cols = params[:cols]
    lim = params[:limit]
    off = params[:offset]
    
    blacklist = ["-", "/", ";", "'", "\"", "flag"]
    
    blacklist.each { |word|
        if cols.include? word
            return "beep boop sqli detected!"
        end
    }

    
    if cols.length > 24 || !/^[0-9]+$/.match?(lim) || !/^[0-9]+$/.match?(off)
        return "bad, no quills for you!"
    end

    @row = db.execute("select %s from quills limit %s offset %s" % [cols, lim, off])

    p @row

    erb :specific
end