Pydio Cells through 4.1.2 allows XSS. Pydio Cells implements the download of files using presigned URLs which are generated using the Amazon AWS SDK for JavaScript [1]. The secrets used to sign these URLs are hardcoded and exposed through the JavaScript files of the web application. Therefore, it is possible to generate valid signatures for arbitrary download URLs. By uploading an HTML file and modifying the download URL to serve the file inline instead of as an attachment, any included JavaScript code is executed when the URL is opened in a browser, leading to a cross-site scripting vulnerability.

Pydio Cells through 4.1.2 allows SSRF. For longer running processes, Pydio Cells allows for the creation of jobs, which are run in the background. The job "remote-download" can be used to cause the backend to send a HTTP GET request to a specified URL and save the response to a new file. The response file is then available in a user-specified folder in Pydio Cells.

Pydio Cells allows users by default to create so-called external users in order to share files with them. By modifying the HTTP request sent when creating such an external user, it is possible to assign the new user arbitrary roles. By assigning all roles to a newly created user, access to all cells and non-personal workspaces is granted.

Directory traversal in the Copy, Move, and Delete features in Pydio Cells 2.2.9 allows remote authenticated users to enumerate personal files (or Cells files belonging to any user) via the nodes parameter (for Copy and Move) or via the Path parameter (for Delete).

Directory traversal in the Compress feature in Pydio Cells 2.2.9 allows remote authenticated users to overwrite personal files, or Cells files belonging to any user, via the format parameter.

Broken access control for user creation in Pydio Cells 2.2.9 allows remote anonymous users to create standard users via the profile parameter. (In addition, such users can be granted several admin permissions via the Roles parameter.)

The following vulnerability applies only to the Pydio Cells Enterprise OVF version 2.0.4. Prior versions of the Pydio Cells Enterprise OVF (such as version 2.0.3) have a looser policy restriction allowing the “pydio” user to execute any privileged command using sudo. In version 2.0.4 of the appliance, the user pydio is responsible for running all the services and binaries that are contained in the Pydio Cells web application package, such as mysqld, cells, among others. This user has privileges restricted to run those services and nothing more.

Pydio Cells 2.0.4 allows any user to upload a profile image to the web application, including standard and shared user roles. These profile pictures can later be accessed directly with the generated URL by any unauthenticated or authenticated user.

In Pydio Cells 2.0.4, once an authenticated user shares a file selecting the create a public link option, a hidden shared user account is created in the backend with a random username. An anonymous user that obtains a valid public link can get the associated hidden account username and password and proceed to login to the web application. Once logged into the web application with the hidden user account, some actions that were not available with the public share link can now be performed.

The update feature for Pydio Cells 2.0.4 allows an administrator user to set a custom update URL and the public RSA key used to validate the downloaded update package. The update process involves downloading the updated binary file from a URL indicated in the update server response, validating its checksum and signature with the provided public key and finally replacing the current application binary. To complete the update process, the application’s service or appliance needs to be restarted. An attacker with administrator access can leverage the software update feature to force the application to download a custom binary that will replace current Pydio Cells binary. When the server or service is eventually restarted the attacker will be able to execute code under the privileges of the user running the application. In the Pydio Cells enterprise appliance this is with the privileges of the user named “pydio”.