Class: LintFu::Plugins::Rails::UnsafeFind

Inherits:
Issue
  • Object
show all
Defined in:
lib/lint_fu/plugins/rails/unsafe_find_checker.rb

Instance Attribute Summary

Attributes inherited from Issue

#confidence, #file, #sexp

Instance Method Summary collapse

Methods inherited from Issue

#brief, #file_basename, #issue_hash, #line, #relative_file

Constructor Details

#initialize(scan, file, sexp, subject) ⇒ UnsafeFind

Returns a new instance of UnsafeFind.



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# File 'lib/lint_fu/plugins/rails/unsafe_find_checker.rb', line 4

def initialize(scan, file, sexp, subject)
  super(scan, file, sexp)
  @subject = subject
end

Instance Method Details

#detail ⇒ Object 



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# File 'lib/lint_fu/plugins/rails/unsafe_find_checker.rb', line 10

def detail
  return "Could a bad guy manipulate <code>#{@subject}</code> and get/change stuff he shouldn't?"
end

#reference_info ⇒ Object 



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# File 'lib/lint_fu/plugins/rails/unsafe_find_checker.rb', line 14

def reference_info
  return <<EOF
h4. What is it?

An unsafe find is an ActiveRecord query that is performed without checking whether the logged-in user is authorized to view or manipulate the resulting models.

h4. When does it happen?

Some trivial examples:

bc. BankAccount.first(params[:id]).destroy
Account.all(:conditions=>{:nickname=>params[:nickname]})

In reality, it is often hard to determine whether a find is safe. Authorization can happen in many ways and the "right" way to do it depends on the application requirements.

Here are some things to consider when evaluating whether a find is safe:

* Is authorization checked beforehand or afterward, e.g. by checking ownership of the model?
* Do the query's conditions scope it in some way to the current user or account?
* How will the results be used? What information is displayed in the view?
* Are the results scoped afterward, e.g. by calling @select@ on the result set?

h4. How do I fix it?

Use named scopes to scope your queries instead of calling the class-level finders:

bc. current_user.bank_accounts.first(params[:id])

If a named scope is not convenient, include conditions that scope the query:

bc. BankAccount.find(:conditions=>{:owner_id=>current_user})

If your authorization rules are so complex that neither of those approaches work, always make sure to perform authorization yourself:

bc. #My bank allows customers to access ANY account on their birthday
@bank_account = BankAccount.first(params[:id])
raise ActiveRecord::RecordNotFound unless current_user.born_on = Date.today
EOF
end