CORS/CSP Configuration

Web browser access to Amazon and Azure storage buckets can sometimes be restricted due to Cross Origin Resource Sharing (CORS) and Content Security Policy (CSP) settings.

The following operations are impaired when accessing bucket content from the Orchestrator UI:

• Uploading files into a storage bucket
• Downloading files from a storage bucket.

• Opening document validation actions or form actions that use images stored in buckets.

  Note: Accessing storage files using activities is not impacted by CORS and CSP policies because they are browser-specific and are validated/enforced at browser level only.

Both CORS and CSP allow whitelisting identified entities in the web application. See below details about each.

CORS

CORS is a mechanism that allows resources on a web page to be accessed across domain boundaries.

Orchestrator web browser access to Amazon and Azure storage buckets can be restricted due to same-origin-policy on the provider side. Successfully accessing the content of such a bucket from the Orchestrator UI requires you to configure the respective provider to allow cross-origin requests from Orchestrator.

Note:

If you change the frontend DNS, you must update the CORS settings of all storage buckets (S3 or compatible), or on all Azure storage accounts that Orchestrator accesses.

Amazon S3

Add a rule that allows GET and PUT requests from Orchestrator. For example:

[
    {
        "AllowedHeaders": [
            "*"
        ],
        "AllowedMethods": [
            "GET",
            "PUT"
        ],
        "AllowedOrigins": [
            "https://cloud.uipath.com"
        ],
        "ExposeHeaders": []
    }
]

See here the official Amazon S3 documentation on the subject of cross-origin resource sharing.

Azure

Enable GET and PUT operations for requests originating from the Orchestrator. For example:

<Cors>
<CorsRule>
<AllowedOrigins>http://cloud.uipath.com</AllowedOrigins>
<AllowedMethods>PUT,GET</AllowedMethods>
<AllowedHeaders>*</AllowedHeaders>
<ExposedHeaders>*</ExposedHeaders>
</CorsRule>
</Cors>

Note: Make sure that the URL does not end in a slash.

See here the official Azure documentation on the subject of cross-origin resource sharing.

CSP

Content Security Policy is a web browser security layer that prevents a web app from making requests outside a trusted set of hosts.

When using storage buckets, Orchestrator automatically allows calls to Azure or Amazon S3.

Important: To prevent CSP issues, use canonical Azure or Amazon names for the container, and avoid vanity URLs.