Why is my IP blocked by some AWS CloudFront services?

Question

I am currently experiencing a 403 Forbidden error when accessing certain websites that are hosted behind AWS CloudFront.  I was able to access these services normally just a few days ago. However, now I receive the following response when trying to connect:

```
HTTP/2 403
server: CloudFront
x-cache: Error from cloudfront
x-amz-cf-pop: NRT57-P10
x-amz-cf-id: r0QPHFImxAfpKaSkndVtJFSwr6g22UeLBMzgJRqtONFz3aXdf6nJCQ==
```
Troubleshooting steps I have tried:
	1.	Verified that my IP is indeed using ipinfo.io
	2.	Changed my User-Agent and tested using curl -A "Mozilla/5.0 ..." https://example.com
	3.	Used a VPN to change my IP, which allowed me to access the service normally
	4.	Checked the CloudFront edge location in the response (NRT57-P10)
	5.	Waited 24+ hours in case it was a temporary block, but the issue persists

Questions:
	•	Does AWS CloudFront implement any automated IP blocking mechanisms that could explain this behavior?
	•	If so, how can I determine why my IP was blocked and request removal?
	•	Is there a way to check if my IP has been blacked due to a false positive?

Any insights or suggestions would be greatly appreciated. Thanks!

Leo K · Answer

Many sites using CloudFront additionally use Web Application Firewall (WAFv2) to filter out unnecessary or likely malicious traffic. There are five AWS-managed IP address lists that are commonly used for this purpose. They're documented here: https://docs.aws.amazon.com/waf/latest/developerguide/aws-managed-rule-groups-ip-rep.html

I'd think it most likely that your IP address might be on the first three lists, which contain IPs that are either hitting AWS's "honeypots" intended to attract malicious parties blindly scanning the whole internet for potential victims, or which have been observed to be actively engaging in attacks or attempts to disrupt the normal operation of sites.

A false positive is quite unlikely, considering how widely these reputation lists are used, but if your IP address is dynamically allocated, it might recently have been used by a bad actor. If your IP address is dynamically allocated, the easiest solution might be to try to change the IP address to a new one.

Riku_Kobayashi · Answer

Hello.

Have you checked the troubleshooting documentation below?  
If you check CloudFront's access log, etc., you may be able to find out why it is being blocked.  
https://repost.aws/knowledge-center/cloudfront-troubleshoot-403-errors

Joanna K · Answer

I can give some more detail on this although kudo's to [Leo K](https://repost.aws/community/users/USS8FyhmOtRWeOsQW4POJsFg) for their response above :-)

**Q:**  Does AWS CloudFront implement any automated IP blocking mechanisms that could explain this behavior?

**A:** No,  however the owner of the CloudFront distribution may have chosen to enable CloudFront geo-blocking or deploy an AWS WAF 'WebACL' with the [AWSManagedIPReputationList](https://docs.aws.amazon.com/waf/latest/developerguide/aws-managed-rule-groups-ip-rep.html#aws-managed-rule-groups-ip-rep-amazon) managed rulegroup included,  or potentially the CloudFront origin has returned the HTTP 403 response code,  itself.

**Q:**  If so, how can I determine why my IP was blocked and request removal?

**A:**  You can raise a billing or technical support case and request dates/times of malicious activities so that you can investigate which client behind the IP caused the issue and remedy the situation,  however we rarely,  if ever,  remove an IP on request.  The IP addresses will be removed from the list when we no longer observe malicious traffic from them for a minimum 24 hours of inactivity.  The required inactivity period is extended, depending on number of attacks the IP participated in.

**Q:** Is there a way to check if my IP has been blacked due to a false positive?

**A:** It **won't** be a false positive - the list is curated automatically and the algorithm is proven,  however you may be unknowingly sharing an egress IP with a malicious or infected client (or your client could itself could an infected device).  End-clients whose requests are being blocked can try the following to unblock e.g:
-  toggle between Wifi and cellular
-  log on/off VPN
-  remove proxy configuration

Why is my IP blocked by some AWS CloudFront services?

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