Troubleshooting HTTP 403 Errors in Amazon CloudFront

Amazon CloudFront is an excellent service for delivering content at high speeds globally. But occasionally, users may encounter HTTP 403 errors with the messages “The request could not be satisfied” or “Access Denied.” This article covers possible causes of these errors and how to troubleshoot to find the root cause.

Domain Name Association Issues with CNAME on Distribution

One common reason for HTTP 403 errors in CloudFront is when the domain name isn’t associated with an alternate domain name (CNAME) on a distribution.

To add a CNAME to your CloudFront distribution configuration, you must follow the instructions from the AWS resource on Adding an Alternate Domain Name (CNAME).

Geographic Restrictions on the Distribution

CloudFront allows you to control the geographic distribution of your content. If you have restricted the geographic distribution of your content, it could potentially result in 403 errors for users outside the allowed regions.

Make sure to carefully review settings in order to avoid these situations.

AWS WAF Blocking the Request

Amazon Web Services Web Application Firewall (AWS WAF) could potentially block requests, leading to a 403 error.

If your CloudFront distribution is configured with AWS WAF, ensure to review the AWS WAF logs and tune your WAF protections.

Errors from Amazon S3 Origin

If your content is being served from Amazon Simple Storage Service (Amazon S3), a misconfiguration could result in 403 errors.

There could be specific reasons based on the type of endpoint you are using:

  • S3 website endpoint, further guidance is available here.
  • S3 REST API endpoint, additional information for troubleshooting is available here.

Errors from Custom Origin

If you’re using a custom origin and it is returning the 403 error, you may need to check the origin HTTP access logs. Directly making requests to the origin also helps identify if the origin is causing errors.

Signed URL or Signed Cookies Configuration Error

If content is private and access is restricted using signed URLs or signed cookies, any misconfigurations here can cause 403 errors as well.

You need to ensure these configurations are error-free as mentioned in the guides:

Distribution Viewer Protocol Policy

Errors could also be as a result of the viewer protocol policy in CloudFront distribution not being configured for HTTP and HTTPS.

Ensure your CloudFront distributions are requiring HTTPS for communication between viewers and CloudFront.

HTTP 403 errors on CloudFront can arise from various reasons. Identifying the origin of these errors is the first step in resolving them and ensuring your users can access content seamlessly.

Tags: #AWS #CloudFront #HTTP403 #Troubleshooting
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