Merge pull request github#11337 from hmac/actionmailbox

Ruby: Model ActionMailbox

Author: hmac

ruby/ql/lib/change-notes/2022-11-30-actionmailbox.md

@@ -0,0 +1,4 @@
+---
+ category: minorAnalysis
+---
+ * Calls to `mail` and `inbound_mail` in `ActionMailbox` controllers are now considered sources of remote input.

ruby/ql/lib/codeql/ruby/Frameworks.qll

@@ -7,6 +7,7 @@ private import codeql.ruby.frameworks.ActionCable
 private import codeql.ruby.frameworks.ActionController
 private import codeql.ruby.frameworks.ActiveJob
 private import codeql.ruby.frameworks.ActionMailer
+private import codeql.ruby.frameworks.ActionMailbox
 private import codeql.ruby.frameworks.ActiveRecord
 private import codeql.ruby.frameworks.ActiveResource
 private import codeql.ruby.frameworks.ActiveStorage

ruby/ql/lib/codeql/ruby/frameworks/ActionMailbox.qll

@@ -0,0 +1,54 @@
+/**
+ * Models the `ActionMailbox` library, which is part of Rails.
+ * Version: 7.0.4.
+ */
+
+private import codeql.ruby.AST
+private import codeql.ruby.Concepts
+private import codeql.ruby.DataFlow
+private import codeql.ruby.dataflow.RemoteFlowSources
+
+/**
+ * Models the `ActionMailbox` library, which is part of Rails.
+ * Version: 7.0.4.
+ */
+module ActionMailbox {
+  private DataFlow::ClassNode controller() {
+    result = DataFlow::getConstant("ActionMailbox").getConstant("Base").getADescendentModule()
+  }
+
+  /**
+   * A call to `mail` on the return value of
+   * `ActionMailbox::Base#inbound_email`, or a direct call to
+   * `ActionMailbox::Base#mail`, which is equivalent. The returned object
+   * contains data from the incoming email.
+   */
+  class Mail extends DataFlow::CallNode {
+    Mail() {
+      this =
+        [
+          controller().getAnInstanceSelf().getAMethodCall("inbound_email").getAMethodCall("mail"),
+          controller().getAnInstanceSelf().getAMethodCall("mail")
+        ]
+    }
+  }
+
+  /**
+   * A method call on a `Mail::Message` object which may return data from a remote source.
+   */
+  private class RemoteContent extends DataFlow::CallNode, RemoteFlowSource::Range {
+    RemoteContent() {
+      this =
+        any(Mail m)
+            .(DataFlow::LocalSourceNode)
+            .getAMethodCall([
+                "body", "to", "from", "raw_source", "subject", "from_address",
+                "recipients_addresses", "cc_addresses", "bcc_addresses", "in_reply_to",
+                "references", "reply_to", "raw_envelope", "to_s", "encoded", "header", "bcc", "cc",
+                "text_part", "html_part"
+              ])
+    }
+
+    override string getSourceType() { result = "ActionMailbox" }
+  }
+}

ruby/ql/test/library-tests/frameworks/action_mailbox/ActionMailbox.expected

@@ -0,0 +1,12 @@
+messageInstances
+| action_mailbox.rb:3:5:3:8 | call to mail |
+| action_mailbox.rb:4:5:4:8 | call to mail |
+| action_mailbox.rb:6:5:6:10 | call to mail |
+| action_mailbox.rb:10:5:10:8 | call to mail |
+| action_mailbox.rb:16:9:16:12 | call to mail |
+remoteFlowSources
+| action_mailbox.rb:3:5:3:13 | call to body |
+| action_mailbox.rb:4:5:4:11 | call to to |
+| action_mailbox.rb:6:5:6:13 | call to to |
+| action_mailbox.rb:10:5:10:18 | call to text_part |
+| action_mailbox.rb:16:9:16:23 | call to raw_source |

ruby/ql/test/library-tests/frameworks/action_mailbox/ActionMailbox.ql

@@ -0,0 +1,7 @@
+private import codeql.ruby.frameworks.ActionMailbox
+private import codeql.ruby.DataFlow
+private import codeql.ruby.dataflow.RemoteFlowSources
+
+query predicate messageInstances(ActionMailbox::Mail c) { any() }
+
+query predicate remoteFlowSources(RemoteFlowSource r) { any() }

ruby/ql/test/library-tests/frameworks/action_mailbox/action_mailbox.rb

@@ -0,0 +1,24 @@
+class A < ActionMailbox::Base
+  def process
+    mail.body
+    mail.to
+    m = inbound_email
+    m.mail.to
+  end
+
+  def other_method
+    mail.text_part
+  end
+end
+
+class B < A
+    def process
+        mail.raw_source
+    end
+end
+
+class C # not a mailbox class
+    def process
+        mail.subject
+    end
+end