Two potential false positives in Brakeman

brakeman.out

+SUMMARY+
+---------------------------+
| Scanned/Reported  | Total |
+---------------------------+
| Controllers       |     1 |
| Models            |     1 |
| Templates         |     1 |
| Errors            |     0 |
| Security Warnings | 2 (1) |
+---------------------------+

+-------------------------------+
|     Warning Type      | Total |
+-------------------------------+
| Attribute Restriction |     1 |
| SQL Injection         |     1 |
+-------------------------------+

+SECURITY WARNINGS+
+--------------------------------------------------------------------------------------------------------------------->>
| Confidence | Class | Method | Warning Type  |                                                                 Messag>>
+--------------------------------------------------------------------------------------------------------------------->>
| Medium     | User  |        | SQL Injection | Possible SQL injection near line 4: scope(:search_by_name, lambda { |n>>
+--------------------------------------------------------------------------------------------------------------------->>

Model Warnings:

+------------------------------------------------------------------------------------------------------+
| Confidence | Model |     Warning Type      |                         Message                         |
+------------------------------------------------------------------------------------------------------+
| High       | User  | Attribute Restriction | Mass assignment is not restricted using attr_accessible |
+------------------------------------------------------------------------------------------------------+

user.rb

class User < ActiveRecord::Base
  attr_protected :admin

  scope :search_by_name, lambda { |name|
    where("LOWER(name) LIKE ?", "%#{name.downcase}%")
  }
end