CVE-2021-43809 (published 2021-12-08T19:15Z)

`Bundler` is a package for managing application dependencies in Ruby. In `bundler` versions before 2.2.33, when working with untrusted and apparently harmless `Gemfile`'s, it is not expected that they lead to execution of external code, unless that's explicit in the ruby code inside the `Gemfile` itself. However, if the `Gemfile` includes `gem` entries that use the `git` option with invalid, but seemingly harmless, values with a leading dash, this can be false. To handle dependencies that come from a Git repository instead of a registry, Bundler uses various commands, such as `git clone`. These commands are being constructed using user input (e.g. the repository URL). When building the commands, Bundler versions before 2.2.33 correctly avoid Command Injection vulnerabilities by passing an array of arguments instead of a command string. However, there is the possibility that a user input starts with a dash (`-`) and is therefore treated as an optional argument instead of a positional one. This can lead to Code Execution because some of the commands have options that can be leveraged to run arbitrary executables. Since this value comes from the `Gemfile` file, it can contain any character, including a leading dash.\n\nTo exploit this vulnerability, an attacker has to craft a directory containing a `Gemfile` file that declares a dependency that is located in a Git repository. This dependency has to have a Git URL in the form of `-u./payload`. This URL will be used to construct a Git clone command but will be interpreted as the upload-pack argument. Then this directory needs to be shared with the victim, who then needs to run a command that evaluates the Gemfile, such as `bundle lock`, inside.\n\nThis vulnerability can lead to Arbitrary Code Execution, which could potentially lead to the takeover of the system. However, the exploitability is very low, because it requires a lot of user interaction. Bundler 2.2.33 has patched this problem by inserting `--` as an argument before any positional arguments to those Git commands that were affected by this issue. Regardless of whether users can upgrade or not, they should review any untrustred `Gemfile`'s before running any `bundler` commands that may read them, since they can contain arbitrary ruby code.

Severity: HIGH
CVSS v2 base score: 9.3 (AV:N/AC:M/Au:N/C:C/I:C/A:C)
CVSS v3 base score: 7.3, HIGH (CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H)

Weakness information:
cwe_id: CWE-88
cwe_name: Improper Neutralization of Argument Delimiters in a Command ('Argument Injection')
description: The product constructs a string for a command to be executed by a separate component
in another control sphere, but it does not properly delimit the
intended arguments, options, or switches within that command string.
extended_description: 
            When creating commands using interpolation into a string, developers may assume that only the arguments/options that they specify will be processed.  This assumption may be even stronger when the programmer has encoded the command in a way that prevents separate commands from being provided maliciously, e.g. in the case of shell metacharacters.  When constructing the command, the developer may use whitespace or other delimiters that are required to separate arguments when the command. However, if an attacker can provide an untrusted input that contains argument-separating delimiters, then the resulting command will have more arguments than intended by the developer.  The attacker may then be able to change the behavior of the command.  Depending on the functionality supported by the extraneous arguments, this may have security-relevant consequences.
         
         

Fix information:
repo_url: https://github.com/rubygems/rubygems
commit_details: repo_url: https://github.com/rubygems/rubygems
author: Simon Fish
author_date: 2021-10-26 17:50:55+01:00
msg: Add require parameter to `bundle add``

Test and ensure "false" is handled

Don't use yield_self to operate on autorequire

Remove duplicate autorequire

Add banner to require option

Don't use json to break down require params

Pass linter
repository: repo_url: https://github.com/rubygems/rubygems
repo_name: rubygems/rubygems
description: Library packaging and distribution for Ruby.
repo_language: Ruby
owner: rubygems
file_changes: filename: cli.rb
change_type: ModificationType.MODIFY
diff: @@ -367,6 +367,7 @@ def binstubs(*gems)
     method_option "version", :aliases => "-v", :type => :string
     method_option "group", :aliases => "-g", :type => :string
     method_option "source", :aliases => "-s", :type => :string
+    method_option "require", :aliases => "-r", :type => :string, :banner => "Adds require path to gem. Provide false, or a path as a string."
     method_option "git", :type => :string
     method_option "branch", :type => :string
     method_option "skip-install", :type => :boolean, :banner =>

programming_language: Ruby
filename: injector.rb
change_type: ModificationType.MODIFY
diff: @@ -113,8 +113,9 @@ def build_gem_lines(conservative_versioning)
         source = ", :source => \"#{d.source}\"" unless d.source.nil?
         git = ", :git => \"#{d.git}\"" unless d.git.nil?
         branch = ", :branch => \"#{d.branch}\"" unless d.branch.nil?
+        require_path = ", :require => #{convert_autorequire(d.autorequire)}" unless d.autorequire.nil?
 
-        %(gem #{name}#{requirement}#{group}#{source}#{git}#{branch})
+        %(gem #{name}#{requirement}#{group}#{source}#{git}#{branch}#{require_path})
       end.join("\n")
     end
 
@@ -269,5 +270,11 @@ def cross_check_for_errors(gemfile_path, original_deps, removed_deps, initial_ge
     def show_warning(message)
       Bundler.ui.info Bundler.ui.add_color(message, :yellow)
     end
+
+    def convert_autorequire(autorequire)
+      autorequire = autorequire.first
+      return autorequire if autorequire == "false"
+      autorequire.inspect
+    end
   end
 end

programming_language: Ruby
filename: add_spec.rb
change_type: ModificationType.MODIFY
diff: @@ -68,6 +68,18 @@
     end
   end
 
+  describe "with --require" do
+    it "adds the require param for the gem" do
+      bundle "add 'foo' --require=foo/engine"
+      expect(bundled_app_gemfile.read).to match(%r{gem "foo",(?: .*,) :require => "foo\/engine"})
+    end
+
+    it "converts false to a boolean" do
+      bundle "add 'foo' --require=false"
+      expect(bundled_app_gemfile.read).to match(/gem "foo",(?: .*,) :require => false/)
+    end
+  end
+
   describe "with --group" do
     it "adds dependency for the specified group" do
       bundle "add 'foo' --group='development'"

programming_language: Ruby
repo_url: https://github.com/rubygems/rubygems
commit_details: repo_url: https://github.com/rubygems/rubygems
author: David Rodríguez
author_date: 2021-12-07 15:34:48+01:00
msg: Changelog for Bundler version 2.2.33
repository: repo_url: https://github.com/rubygems/rubygems
repo_name: rubygems/rubygems
description: Library packaging and distribution for Ruby.
repo_language: Ruby
owner: rubygems
file_changes: filename: CHANGELOG.md
change_type: ModificationType.MODIFY
diff: @@ -1,3 +1,32 @@
+# 2.2.33 (December 7, 2021)
+
+## Security fixes:
+
+  - Pass "--" to git commands to separate positional and optional args [#5142](https://github.com/rubygems/rubygems/pull/5142)
+
+## Enhancements:
+
+  - Accept pull request URLs as github source [#5126](https://github.com/rubygems/rubygems/pull/5126)
+  - Add `--version` parameter to `bundle info` command [#5137](https://github.com/rubygems/rubygems/pull/5137)
+  - Let original `Errno::EACCES` error be raised in compact index updater [#5110](https://github.com/rubygems/rubygems/pull/5110)
+  - Improve gemfile-lockfile source equivalence errors [#5120](https://github.com/rubygems/rubygems/pull/5120)
+  - Avoid float-to-string loss of characters in GitHub Actions configuration labels in new gem template [#5089](https://github.com/rubygems/rubygems/pull/5089)
+  - Add an initial rbs template to `bundle gem` skeleton [#5041](https://github.com/rubygems/rubygems/pull/5041)
+  - Avoid shared libraries not getting environment passed right after argv in memory when `bundle exec` is used [#4815](https://github.com/rubygems/rubygems/pull/4815)
+
+## Bug fixes:
+
+  - Don't cleanup paths from gems already activated from `$LOAD_PATH` [#5111](https://github.com/rubygems/rubygems/pull/5111)
+  - Fix handling prereleases of 0 versions, like 0.0.0.dev or 0.0.0.SNAPSHOT [#5116](https://github.com/rubygems/rubygems/pull/5116)
+  - Fix escape of filenames in `bundle doctor` [#5102](https://github.com/rubygems/rubygems/pull/5102)
+  - Don't unlock dependencies when running `bundle install` after changing global source [#5090](https://github.com/rubygems/rubygems/pull/5090)
+  - Fix missing locked specs when depended on another platform [#5092](https://github.com/rubygems/rubygems/pull/5092)
+  - Fix `bundle info` sometimes claiming that bundler has been deleted [#5097](https://github.com/rubygems/rubygems/pull/5097)
+
+## Documentation:
+
+  - Ignore to generate the documentation from vendored libraries [#5118](https://github.com/rubygems/rubygems/pull/5118)
+
 # 2.2.32 (November 23, 2021)
 
 ## Enhancements:

programming_language: Markdown