lib/brakeman/checks/check_mime_type_dos.rb
require 'brakeman/checks/base_check'
class Brakeman::CheckMimeTypeDoS < Brakeman::BaseCheck
Brakeman::Checks.add self
@description = "Checks for mime type denial of service (CVE-2016-0751)"
def run_check
fix_version = case
when version_between?("3.0.0", "3.2.22")
"3.2.22.1"
when version_between?("4.0.0", "4.1.14")
"4.1.14.1"
when version_between?("4.2.0", "4.2.5")
"4.2.5.1"
else
return
end
return if has_workaround?
message = msg(msg_version(rails_version), " is vulnerable to denial of service via mime type caching ", msg_cve("CVE-2016-0751"), ". Upgrade to ", msg_version(fix_version))
warn :warning_type => "Denial of Service",
:warning_code => :CVE_2016_0751,
:message => message,
:confidence => :medium,
:gem_info => gemfile_or_environment,
:link_path => "https://groups.google.com/d/msg/rubyonrails-security/9oLY_FCzvoc/w9oI9XxbFQAJ",
:cwe_id => [399]
end
def has_workaround?
tracker.find_call(target: :Mime, method: :const_set).any? do |match|
arg = match[:call].first_arg
symbol? arg and arg.value == :LOOKUP
end
end
end