Ruby on Rails Static Analysis Security Tool

Brakeman 2.4.0 Released

This is a fairly big release with some significant changes (especially for SQL injection warnings), so please test carefully. Existing warnings and fingerprints may change.

Changes since 2.3.1:

  • Fingerprint attribute warnings individually (Case Taintor)
  • Add check for uses of OpenSSL::SSL::VERIFY_NONE (Aaron Bedra)
  • Detect SQL injection raw SQL queries using connection(#434)
  • Fix false positives when SQL methods are not called on AR models (#423, Aaron Bedra)
  • Reduce false positives for SQL injection in string building
  • More accurate user input marking for SQL injection warnings
  • Detect SQL injection in delete_all/destroy_all
  • Add support for Rails LTS versions (#422)
  • Parse exact versions from Gemfile.lock for all gems (#431)
  • Ignore generators in lib/ directory
  • No longer raise exceptions if a class name cannot be determined
  • Update to RubyParser 3.4.0

Attribute Warning Fingerprints

Case Taintor noted that ignoring one warning about dangerous mass assignable attributes ignored all such warnings for the same model. Then he fixed it, yay!

Please note this means fingerprints for warnings about “dangerous attributes” in attr_accessible will change. If you are currently ignoring some of these warnings, you will need to re-ignore them.

Also, the messages for these warnings have changed and the attribute name will now be in the “code” value in JSON reports.


Check for SSL Verification

Aaron Bedra has contributed a new check for instances of verify_mode on HTTPS connections being set to OpenSSL::SSL::VERIFY_NONE. This bypasses any checks OpenSSL has for verifying the SSL certificate is legitimate, allowing easy man-in-the-middle attacks.

This new check has a new warning type (“SSL Verification Bypass”) and warning code (71).


SQL Injection in Raw Queries

ActiveRecord::Core#connection or ActiveRecord::Base.connection or ActiveRecord::Base#connection can be used to send queries directly to the database connection without any protection. There are several ways of doing this, most of which are hopefully now covered by Brakeman.


Fewer SQL Injection False Positives

Many changes were made in this release to reduce false positives related to SQL injection warnings and to improve the accuracy of reported issues.

First, Aaron Bedra fixed Brakeman to not warn about query-like methods that were innocently called on non-ActiveRecord objects. (changes)

For example, this:

find_by_sql("SELECT * FROM stuff WHERE thing = " + self.class.sanitize_sql(thing))

would have generated a warning which indicated "SELECT * FROM stuff WHERE thing = " + self.class.sanitize_sql(thing) was a dangerous value. Now it will not warn at all.

As another example, code like this

options = {}

if params[:sort_order] == 'ascending'
  sort_order = 'ASC'
  sort_order = 'DESC'

options[:order] = 'updated_at ' + sort_order

would create a warning about ("updated_at " + ("ASC" or "DESC")). Now Brakeman will recognize that these are all just strings and not warn.

Many warnings will also just be more accurate:

query = "SELECT sum(stuff) " +
      "FROM (SELECT other_stuff FROM #{table} WHERE id = #{id}) " +
      "AS item, bgs " +
      "WHERE ST_Contains(item.geometry, bgs.the_point);"


This used to warn on the entire query! Now it will just warn about table.

#to_s calls are ignored now and their targets considered instead.

Additionally, Brakeman should no longer warn about method calls ending in _id, since those generally refer to foreign keys. Note, however, that local variables ending in _id will still produce warnings.

In general, fingerprints should not change for existing warnings, since the user_input value is not included in the fingerprint.


SQL Injection in Deletions

Brakeman will now look for SQL injection in delete_all and destroy_all which allow raw SQL strings.


Support for Rails LTS

RailsLTS provides security patch backporting to Rails 2.3.18. They now include an internal version number in Gemfile.lock, which allows Brakeman to avoid warning about fixed vulnerabilities in applications using RailsLTS.


Gemfile Parsing

Previously, Brakeman only checked Gemfile.lock for specific gems. Now it “parses” the entire file and can track all gem versions. (bundler-audit is recommended for checking gems for vulnerable versions.) This helps when Brakeman is checking for gem usage but the gem is an indirect dependency.

Also, a minor issue was fixed for those Gemfiles that do weird things and call gem with non-string arguments.


Generators are Ignored

Any path in lib/ containing generators will now be ignored. This is mainly because there are .rb files in there that are actually templates, but Brakeman tries to parse them and fails because they aren’t really Ruby.


Exceptions for Class Names

Previously, Brakeman actually raised and caught exceptions if a class name could not be determined from a Sexp. Now it just returns nil. This should remove some errors and possibly make some scans faster.


RubyParser Update

The RubyParser dependency has been updated to 3.4.0. This release is much faster, along with lots of other good changes.

However, please note that line numbers for warnings involving heredocs may change. They will be slightly closer, but not exactly accurate.



The SHA1 sums for this release are

c9d840b6fca08f61b3abbd1fa109cf66be19fccc brakeman-2.4.0.gem 5bad89c43f7ab78bd40dfd6f71aac3d034ccaa0a brakeman-min-2.4.0.gem

Reporting Issues

Please report any issues with this release! Take a look at this guide to reporting Brakeman problems.

Also consider following @brakeman on Twitter or joining the mailing list.