AWS CloudFront 📅 2026-02-02

How to Resolve HTTP 403 Permission Denied in Amazon CloudFront

As SREs and engineers, encountering an HTTP 403 Permission Denied error from an Amazon CloudFront distribution can halt content delivery and impact user experience. This guide provides a structured approach to diagnosing and resolving 403 errors, focusing on common misconfigurations within CloudFront, S3, and AWS WAF.

🚨 Symptoms & Diagnosis

When your CloudFront distribution returns a 403, it signifies that access to the requested resource has been explicitly denied. Common signatures include:

HTTP 403 Permission Denied
HTTP 403 Forbidden
HTTP 403 (Invalid method)
Exit Code: 403
CloudFront Access Denied
AWS WAF blocked request
S3 Access Denied (403 Forbidden)

Root Cause: HTTP 403 errors in CloudFront typically stem from permission issues at the origin (e.g., S3 bucket policies, IAM roles), restrictive CloudFront distribution settings (e.g., OAC/OAI, allowed HTTP methods, protocol policies, geo-restrictions), or active AWS WAF rules blocking legitimate requests.

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🛠️ Solutions

Below are structured solutions to troubleshoot and resolve CloudFront 403 errors. Always invalidate your CloudFront cache (/*) after making configuration changes to ensure they take effect promptly.

Verify Origin Accessibility (Quick Diagnostic)

Before diving deep into CloudFront configurations, isolate the problem's source by checking if your origin is directly accessible. This helps determine if the issue lies with CloudFront's configuration or the origin itself.

Immediate Mitigation: Verify Origin Accessibility

Test direct access to your S3 bucket or custom origin to narrow down whether the 403 originates from CloudFront or upstream at the origin.

1. Identify your origin domain (e.g., my-bucket.s3.amazonaws.com or my-custom-origin.example.com).
2. Make a direct HTTP/HTTPS request to the origin for the specific object.
3. Compare the response code. If the direct request also returns a 403, the problem is likely at the origin. If it succeeds, the issue is within CloudFront.

# Test direct access to an S3 origin
curl -I https://my-bucket.s3.amazonaws.com/path/to/object

# Test direct access to a custom origin
curl -I https://my-custom-origin.example.com/path/to/object

# Compare with CloudFront response
curl -I https://d123456.cloudfront.net/path/to/object

Enable S3 Origin Access Control (OAC) / Origin Access Identity (OAI)

For S3 origins, CloudFront requires explicit permission to fetch private objects. Origin Access Control (OAC) is the recommended modern approach, replacing Origin Access Identity (OAI) for enhanced security and functionality.

Best Practice Fix: Configure S3 Origin Access Control (OAC)

Grant CloudFront secure access to private S3 buckets. OAC is the current best practice for securing S3 origins.

AWS Console / GUIAWS CLI

1. Open the AWS CloudFront console.
2. Select your distribution.
3. Navigate to the Origins tab.
4. Select the S3 origin you wish to configure and click Edit.
5. Under Origin access, select Origin access control settings.
6. Choose to Create new OAC or select an existing one.
7. Click Update.
8. CloudFront will display a bucket policy statement. Copy this statement.
9. Open the S3 console, navigate to your bucket, then Permissions > Bucket policy.
10. Paste the copied policy statement into the bucket policy editor and Save changes. This policy grants s3:GetObject permission to the CloudFront OAC principal.
11. Invalidate your CloudFront cache: Go to the Invalidations tab, click Create invalidation, and enter /* as the path to clear all cached objects.

# 1. (Optional) Get existing bucket policy to review
aws s3api get-bucket-policy --bucket my-bucket

# 2. Create a new Origin Access Control (OAC)
# Adjust Name and CallerReference as needed
OAC_CONFIG=$(aws cloudfront create-origin-access-control --origin-access-control-config '{"CallerReference":"my-oac-ref-'"$(date +%s)"'", "Name":"my-oac-for-cloudfront", "OriginAccessControlOriginType":"s3", "SigningBehavior":"always", "SigningProtocol":"sigv4"}' --output json)
echo "Created OAC: $OAC_CONFIG"
# Extract OAC ID: jq -r '.OriginAccessControl.Id' <<< "$OAC_CONFIG"

# 3. Update CloudFront distribution to use the OAC
# First, get the current distribution configuration and its ETag
DIST_ID="D123456ABCDEF" # Replace with your distribution ID
DIST_CONFIG=$(aws cloudfront get-distribution-config --id "$DIST_ID" --output json)
ETAG=$(jq -r '.ETag' <<< "$DIST_CONFIG")

# Modify the distribution config to use OAC for your S3 origin
# You'll need to identify the correct origin in the JSON structure
# Example (assuming first origin is S3 and you want to set OAC):
# For OAC, the S3OriginConfig needs to have OriginAccessControlId set, and OriginAccessIdentity should be empty.
jq '.DistributionConfig.Origins.Items[0].S3OriginConfig.OriginAccessControlId = "YOUR_OAC_ID_HERE" | .DistributionConfig.Origins.Items[0].S3OriginConfig.OriginAccessIdentity = ""' <<< "$DIST_CONFIG" > distribution-config-update.json

# Update the distribution (DANGEROUS: Backup original config first!)
!!! warning "Caution: Configuration Changes"
    Updating a CloudFront distribution can cause service interruptions or unexpected behavior if not done carefully. Always review changes and test thoroughly.

# aws cloudfront update-distribution --id "$DIST_ID" --if-match "$ETAG" --distribution-config file://distribution-config-update.json

# 4. Update the S3 bucket policy to grant OAC access
# CloudFront console provides the exact policy. Manually construct or obtain.
# Example policy structure (replace 'YOUR_BUCKET_NAME', 'YOUR_OAC_ARN'):
# Note: For OAC, the principal ARN is usually from the CloudFront service principal.
# The CloudFront console provides the precise bucket policy JSON to use.
# The ARN for OAC is derived from the OAC ID, e.g., arn:aws:cloudfront::ACCOUNT_ID:origin-access-control/OAC_ID
# However, the bucket policy principal for OAC is usually a service principal like "cloudfront.amazonaws.com".
# Best practice is to get the policy from the CloudFront console after setting OAC.

# Placeholder for bucket policy (ensure to use the one from CloudFront console)
cat << EOF > bucket-policy.json
{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "AllowCloudFrontOACAccess",
            "Effect": "Allow",
            "Principal": {
                "Service": "cloudfront.amazonaws.com"
            },
            "Action": "s3:GetObject",
            "Resource": "arn:aws:s3:::my-bucket/*",
            "Condition": {
                "StringEquals": {
                    "aws:SourceArn": "arn:aws:cloudfront::YOUR_ACCOUNT_ID:distribution/YOUR_DISTRIBUTION_ID"
                }
            }
        }
    ]
}
EOF

# Apply the bucket policy (replace 'my-bucket' and update JSON)
!!! warning "Caution: Security Risk"
    Modifying S3 bucket policies can grant or restrict access to your data. Ensure the policy is correctly scoped to avoid unintended public access or denial of service.

# aws s3api put-bucket-policy --bucket my-bucket --policy file://bucket-policy.json

# 5. Invalidate CloudFront cache
aws cloudfront create-invalidation --distribution-id "$DIST_ID" --paths '/*'

Check and Update S3 Bucket Policy

Even with OAC/OAI, the S3 bucket policy must explicitly allow s3:GetObject permission for the CloudFront principal.

Best Practice Fix: Validate S3 Bucket Policy

Confirm the S3 bucket policy explicitly grants s3:GetObject permissions to your CloudFront distribution's OAC/OAI.

AWS Console / GUIAWS CLI

1. Open the S3 console and navigate to your bucket.
2. Go to the Permissions tab.
3. Review the Bucket policy.
4. Ensure there is an Allow statement that grants the CloudFront OAC principal ("Service": "cloudfront.amazonaws.com" with aws:SourceArn condition) or OAI canonical user ("CanonicalUser": "OAI_CANONICAL_ID") the s3:GetObject action for the relevant resources (arn:aws:s3:::your-bucket-name/*).
5. If the policy is missing or incorrect, add the correct statement (often provided when setting up OAC in CloudFront).
6. Save changes.

# Retrieve and inspect the current S3 bucket policy
aws s3api get-bucket-policy --bucket my-bucket --output json | jq '.Policy | fromjson'

# Example of a correct policy fragment for OAC (replace placeholders)
# Refer to the policy generated by the CloudFront console for exact principal and condition.
# The 'Condition' with 'aws:SourceArn' is crucial for OAC.
cat << EOF > correct-bucket-policy.json
{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Sid": "AllowCloudFrontOAC",
            "Effect": "Allow",
            "Principal": {
                "Service": "cloudfront.amazonaws.com"
            },
            "Action": "s3:GetObject",
            "Resource": "arn:aws:s3:::my-bucket/*",
            "Condition": {
                "StringEquals": {
                    "aws:SourceArn": "arn:aws:cloudfront::YOUR_ACCOUNT_ID:distribution/YOUR_DISTRIBUTION_ID"
                }
            }
        }
    ]
}
EOF

# Apply the updated bucket policy
!!! warning "Caution: Security Risk"
    Applying an incorrect bucket policy can lead to data exposure or deny legitimate access. Verify the policy thoroughly before applying.

# aws s3api put-bucket-policy --bucket my-bucket --policy file://correct-bucket-policy.json

Verify CloudFront Allowed HTTP Methods

If your application uses HTTP methods beyond GET and HEAD (e.g., POST, PUT, DELETE), CloudFront must be configured to allow and forward these methods to the origin. A 403 (Invalid method) often points here.

Best Practice Fix: Configure Allowed HTTP Methods

Ensure your CloudFront distribution's cache behaviors permit all necessary HTTP methods used by your clients.

AWS Console / GUIAWS CLI

1. Open the CloudFront console.
2. Select your distribution.
3. Go to the Behaviors tab.
4. Select the relevant cache behavior (or the default behavior) and click Edit.
5. Under Allowed HTTP methods, choose the option that includes all methods your application requires (e.g., GET, HEAD, OPTIONS, PUT, POST, PATCH, DELETE).
6. Click Save changes.
7. Invalidate the cache with path /*.

DIST_ID="D123456ABCDEF" # Replace with your distribution ID

# Get current distribution configuration to inspect allowed methods
aws cloudfront get-distribution-config --id "$DIST_ID" --output json | jq '.DistributionConfig.DefaultCacheBehavior.AllowedMethods'

# To update, first get the config and ETag
DIST_CONFIG=$(aws cloudfront get-distribution-config --id "$DIST_ID" --output json)
ETAG=$(jq -r '.ETag' <<< "$DIST_CONFIG")

# Modify the AllowedMethods for the default cache behavior
# Example: Allow all methods (adjust to your specific needs)
jq '.DistributionConfig.DefaultCacheBehavior.AllowedMethods.Items = ["HEAD", "GET", "OPTIONS", "PUT", "POST", "PATCH", "DELETE"] | .DistributionConfig.DefaultCacheBehavior.AllowedMethods.Quantity = 7' <<< "$DIST_CONFIG" > distribution-config-methods-update.json

# Update the distribution
!!! warning "Caution: Configuration Changes"
    Modifying allowed HTTP methods can expose your origin to unwanted requests if not properly secured. Review your origin's security posture.

# aws cloudfront update-distribution --id "$DIST_ID" --if-match "$ETAG" --distribution-config file://distribution-config-methods-update.json

# Invalidate cache
aws cloudfront create-invalidation --distribution-id "$DIST_ID" --paths '/*'

Fix Viewer Protocol Policy Mismatch

A Viewer Protocol Policy set to HTTPS only will result in 403s for clients attempting to access content over HTTP.

Best Practice Fix: Align Viewer Protocol Policy

Configure the viewer protocol policy to match how your clients are expected to access your content (HTTP, HTTPS, or redirect). Redirect HTTP to HTTPS is generally recommended.

AWS Console / GUIAWS CLI

1. Open the CloudFront console.
2. Select your distribution.
3. Go to the Behaviors tab.
4. Select the relevant cache behavior and click Edit.
5. Under Viewer protocol policy, choose:
   • Allow HTTP and HTTPS (if you support both, but generally not recommended for security).
   • Redirect HTTP to HTTPS (recommended for most public websites).
   • HTTPS only (if all traffic must use HTTPS).
6. Click Save changes.
7. Invalidate the cache.

DIST_ID="D123456ABCDEF" # Replace with your distribution ID

# Get current distribution config to check ViewerProtocolPolicy
aws cloudfront get-distribution-config --id "$DIST_ID" --output json | jq '.DistributionConfig.DefaultCacheBehavior.ViewerProtocolPolicy'

# To update, get config and ETag
DIST_CONFIG=$(aws cloudfront get-distribution-config --id "$DIST_ID" --output json)
ETAG=$(jq -r '.ETag' <<< "$DIST_CONFIG")

# Modify ViewerProtocolPolicy (e.g., to 'redirect-to-https')
jq '.DistributionConfig.DefaultCacheBehavior.ViewerProtocolPolicy = "redirect-to-https"' <<< "$DIST_CONFIG" > distribution-config-protocol-update.json

# Update the distribution
!!! warning "Caution: Configuration Changes"
    Changing the viewer protocol policy can impact client connectivity. Ensure your application handles HTTPS redirects correctly.

# aws cloudfront update-distribution --id "$DIST_ID" --if-match "$ETAG" --distribution-config file://distribution-config-protocol-update.json

# Invalidate cache
aws cloudfront create-invalidation --distribution-id "$DIST_ID" --paths '/*'

Audit and Fix AWS WAF Rules

AWS WAF can block requests before they even reach your origin. Overly aggressive or misconfigured WAF rules are a common cause of 403s.

Best Practice Fix: Review AWS WAF Configuration

Examine your Web ACLs and associated rules for any blocks that might be inadvertently affecting legitimate CloudFront traffic.

AWS Console / GUIAWS CLI

1. Open the AWS WAF console.
2. Ensure the region is set to Global (CloudFront).
3. Go to Web ACLs and select the Web ACL attached to your CloudFront distribution.
4. Review each rule in the Web ACL. Look for rules that might be blocking based on IP addresses, geographical locations, headers, or request patterns relevant to your traffic.
5. If CloudWatch Logs for WAF are enabled, check for BLOCKED actions to identify which specific rules are triggering 403s.
6. Edit or disable any overly restrictive rules. Consider setting rules to Count mode initially to observe their impact without blocking.
7. Test with curl from a blocked client/region to verify the fix.

# List Web ACLs in CloudFront scope
aws wafv2 list-web-acls --scope CLOUDFRONT --region us-east-1

# Get details of a specific Web ACL (replace with your Web ACL name and ID)
# You'll need the Web ACL ARN (e.g., arn:aws:wafv2:us-east-1:123456789012:global/webacl/my-web-acl/a1b2c3d4)
# Or get ID and Name from list-web-acls output
WEB_ACL_NAME="my-web-acl"
WEB_ACL_ID="a1b2c3d4-e5f6-7890-1234-567890abcdef" # Replace with your Web ACL ID
WEB_ACL_ARN="arn:aws:wafv2:us-east-1:123456789012:global/webacl/$WEB_ACL_NAME/$WEB_ACL_ID"

aws wafv2 get-web-acl --name "$WEB_ACL_NAME" --scope CLOUDFRONT --id "$WEB_ACL_ID" --region us-east-1 --output json | jq '.WebACL.Rules'

# If CloudWatch Logs are configured for WAF, tail the logs for blocked requests:
# Replace '/aws/wafv2/cloudfront/my-web-acl' with your specific log group name
aws logs tail /aws/wafv2/cloudfront/my-web-acl --follow 2>/dev/null | grep BLOCKED

Check Geographic Restrictions

CloudFront's geo-restriction feature can block access based on the client's country, leading to 403 errors.

Best Practice Fix: Review Geo-Restrictions

Verify that your CloudFront geo-restriction settings are not blocking legitimate users based on their geographic location.

AWS Console / GUIAWS CLI

1. Open the CloudFront console.
2. Select your distribution.
3. Go to the Restrictions tab.
4. Review the Geo-restriction settings. If enabled, verify that the client's country is not in the Block List.
5. Adjust the restriction list or disable geo-restrictions if necessary.
6. Invalidate the cache.

DIST_ID="D123456ABCDEF" # Replace with your distribution ID

# Get geo-restriction configuration
aws cloudfront get-distribution-config --id "$DIST_ID" --output json | jq '.DistributionConfig.Restrictions.GeoRestriction'

# To update, get config and ETag
DIST_CONFIG=$(aws cloudfront get-distribution-config --id "$DIST_ID" --output json)
ETAG=$(jq -r '.ETag' <<< "$DIST_CONFIG")

# Example: Disable geo-restrictions
# jq '.DistributionConfig.Restrictions.GeoRestriction.RestrictionType = "none"' <<< "$DIST_CONFIG" > distribution-config-georestrict-update.json

# Example: Update a blacklist (replace countries)
# jq '.DistributionConfig.Restrictions.GeoRestriction = {"RestrictionType": "blacklist", "Quantity": 2, "Items": ["RU", "KP"]}' <<< "$DIST_CONFIG" > distribution-config-georestrict-update.json

# Update the distribution
!!! warning "Caution: Configuration Changes"
    Modifying geo-restrictions can impact content availability for users in different regions. Ensure compliance with content licensing and distribution rights.

# aws cloudfront update-distribution --id "$DIST_ID" --if-match "$ETAG" --distribution-config file://distribution-config-georestrict-update.json

# Invalidate cache
aws cloudfront create-invalidation --distribution-id "$DIST_ID" --paths '/*'

Validate Signed URLs and Signed Cookies

If you're using signed URLs or cookies for restricted content, a 403 can indicate an invalid signature, expired URL, or incorrect policy.

Best Practice Fix: Verify Signed URL/Cookie Configuration

Ensure signed URLs or cookies are generated correctly with valid key pairs, policies, and expiration times.

Manual / Code ReviewAWS CLI (Example for Signed URL)

1. Verify that the CloudFront key pair used for signing is correctly configured and active in your AWS account.
2. Check the Expires parameter in the signed URL or the CloudFront-Expires field in the signed cookie. Ensure it has not passed.
3. Confirm that the URL path in the signed request precisely matches the resource path you're trying to access in the origin.
4. Review the code generating the signed URL/cookie to ensure the private key is correctly used and the signature is computed according to CloudFront's requirements.
5. Generate a new signed URL/cookie with an extended expiration and test.

# This is an example to generate a signed URL using the CloudFront CLI command.
# Requires a pre-configured CloudFront key pair and its ID.
# Replace D123456ABCDEF with your distribution ID.
# Replace /path/to/private-key.pem with your private key file.
# Replace APKAJ123456789ABCDE with your active CloudFront key pair ID.
# Adjust the --date-less-than (expiration) as needed.

# Example: Generating a signed URL for an object (requires CloudFront key pair)
aws cloudfront sign --distribution-id D123456ABCDEF \
                    --private-key-file /path/to/private-key.pem \
                    --key-pair-id APKAJ123456789ABCDE \
                    --date-less-than 2026-02-09T16:20:13Z \
                    https://d123456.cloudfront.net/path/to/object

Check Custom Origin Firewall and Security Groups

For custom origins (e.g., EC2 instances, load balancers), network access controls like firewalls or security groups must permit inbound traffic from CloudFront's IP ranges.

Best Practice Fix: Configure Custom Origin Network Access

Ensure your custom origin's firewall, network ACLs, or security groups explicitly allow inbound traffic from CloudFront's published IP ranges on the required ports (80/443).

Linux Server / AWS Security GroupsAWS CLI / Bash

1. Identify the current CloudFront IP ranges from AWS documentation.
2. For EC2/Load Balancers:
   • Open the Amazon EC2 console.
   • Navigate to Security Groups.
   • Find the security group(s) associated with your custom origin (EC2 instance, ALB, etc.).
   • Verify inbound rules for ports 80 (HTTP) and/or 443 (HTTPS) allow traffic from CloudFront's IP ranges. Add new Ingress rules if missing.
3. For On-Premise / Other Cloud Servers:
   • SSH into your custom origin server.
   • Check active firewall rules (e.g., iptables, ufw, firewalld).
   • Ensure that CloudFront's IP ranges are permitted to access your web server's ports (typically 80/443).
   • Add or modify rules as necessary.

# Retrieve current CloudFront IP ranges (these change, so always fetch latest)
# AWS publishes these ranges in JSON format. You need to parse the 'CLOUDFRONT' service ranges.
# For simplicity, we assume you have the current CIDRs.

# Example: Checking iptables rules on a Linux server
sudo iptables -L -n | grep -E '(80|443)'

# Example: Checking ufw rules on a Linux server
sudo ufw status

# Test connectivity from CloudFront's perspective (conceptual, use an actual CloudFront IP if possible)
# This example uses a placeholder IP. In reality, you'd test from a machine
# within one of CloudFront's actual IP ranges, or use CloudFront logs for indications.
curl -I -H 'Host: my-custom-origin.example.com' https://203.0.113.0:443 # Placeholder IP

# Example: Add an EC2 Security Group rule for CloudFront IP range
# Replace sg-12345678 with your security group ID.
# Replace 204.246.164.0/22 with an actual CloudFront IP range.
!!! warning "Caution: Network Security"
    Modifying security group or firewall rules can expose your origin to unintended traffic or block legitimate access. Exercise extreme care.

# aws ec2 authorize-security-group-ingress \
#     --group-id sg-12345678 \
#     --protocol tcp \
#     --port 443 \
#     --cidr 204.246.164.0/22 \
#     --description "Allow CloudFront HTTPS"

Verify Correct Object Path and Existence

A 403 can sometimes mask a "Not Found" error if the origin server is configured to return 403 for missing objects, or if a Host header mismatch occurs.

Immediate Mitigation: Validate Object Path

Ensure the requested URL path precisely matches the object's location in your origin and that the object actually exists.

1. Double-check the full URL being requested through CloudFront.
2. Compare this path to the actual object location in your S3 bucket or custom origin.
3. For S3, use the S3 console or AWS CLI to list objects and confirm existence.
4. Look for common typos, incorrect casing, or missing path prefixes/suffixes.
5. If using S3 REST API endpoints directly, ensure the Host header is not being forwarded by CloudFront.

# List S3 bucket contents to verify object path
aws s3 ls s3://my-bucket/path/to/ --recursive

# Check for specific object existence using head-object (returns 404 if not found)
aws s3api head-object --bucket my-bucket --key path/to/object

# Test direct access to the S3 object URL (bypassing CloudFront)
curl -I https://my-bucket.s3.amazonaws.com/path/to/object

Review CloudFront Logs for Detailed Error Context

CloudFront access logs provide granular details about every request, including the HTTP status code, viewer IP, and CloudFront's response. This is invaluable for deep diagnostics.

Best Practice Fix: Enable and Analyze CloudFront Logs

Configure CloudFront access logging to an S3 bucket and use log analysis tools to pinpoint the exact cause of 403 errors.

AWS Console / GUIAWS CLI / Bash

1. Open the CloudFront console.
2. Select your distribution.
3. Go to the Logging tab.
4. Enable logging by selecting an S3 bucket to store the logs. (If not already enabled).
5. Wait for log files to appear in your S3 bucket (this can take up to an hour).
6. Download the log files from S3.
7. Use text editors, grep, or log analysis tools (e.g., Athena, CloudWatch Logs Insights) to search for entries with 403 status codes.
8. Analyze associated fields like c-ip (client IP), cs-uri-stem (requested path), x-edge-result-type (CloudFront's determination of error cause), x-edge-response-result-type (origin's response), and x-waf-action (if WAF is involved).

DIST_ID="D123456ABCDEF" # Replace with your distribution ID

# To enable logging, first get current config and ETag
# Modify DistributionConfig.Logging to enable it and specify S3 bucket
# For example:
# .DistributionConfig.Logging.Enabled = true
# .DistributionConfig.Logging.Bucket = "my-log-bucket.s3.amazonaws.com"
# Then update the distribution.
!!! warning "Caution: Configuration Changes"
    Enabling or modifying logging for CloudFront impacts your S3 storage costs and requires appropriate S3 bucket policies.

# aws cloudfront update-distribution --id "$DIST_ID" --if-match "$ETAG" --distribution-config file://distribution-config-logging-update.json

# Download logs from your S3 log bucket
# Replace 'my-log-bucket/cloudfront-logs/' with your actual log path
aws s3 cp s3://my-log-bucket/cloudfront-logs/ ./logs/ --recursive

# Search for 403 errors in compressed log files
zcat logs/*.gz | awk '$9 == 403 {print $0}' | head -20

# For more advanced analysis, consider using AWS Athena or CloudWatch Logs Insights.
# If CloudFront logs are sent to CloudWatch, use:
# aws logs tail /aws/cloudfront/my-distribution --follow 2>/dev/null | grep 403

Invalidate CloudFront Cache After Configuration Changes

After implementing any solution, CloudFront might still serve stale content from its cache. An invalidation forces CloudFront to fetch fresh content from the origin, ensuring your changes take effect.

Immediate Mitigation: Invalidate CloudFront Cache

Clear the CloudFront cache to ensure newly applied configurations or permissions are immediately reflected.

AWS Console / GUIAWS CLI

1. Open the CloudFront console.
2. Select your distribution.
3. Go to the Invalidations tab.
4. Click Create invalidation.
5. Enter /* as the path pattern to invalidate all objects (or more specific paths if you know the affected objects).
6. Click Create invalidation.
7. Monitor the invalidation status. It typically completes within 1-5 minutes.

DIST_ID="D123456ABCDEF" # Replace with your distribution ID

# Create an invalidation for all objects
aws cloudfront create-invalidation --distribution-id "$DIST_ID" --paths '/*'

# List invalidations for a distribution
aws cloudfront list-invalidations --distribution-id "$DIST_ID"

# Get details of a specific invalidation
# Replace I123456ABCDEF with your invalidation ID
# aws cloudfront get-invalidation --distribution-id "$DIST_ID" --id I123456ABCDEF

🧩 Technical Context (Visualized)

An HTTP 403 Permission Denied error from Amazon CloudFront indicates a request was blocked at some point in the content delivery pipeline. This can happen at the CloudFront distribution level itself, due to restrictions like geo-blocking or disallowed methods, or it can be a transparent pass-through of an access denial from the origin server (e.g., an S3 bucket or custom HTTP server). AWS WAF, if integrated, also acts as a crucial pre-origin security layer that can block requests before CloudFront processes them fully or forwards them to the origin.

graph TD
    A[Client Request] --> B{CloudFront Distribution};
    B -- Config/Restrictions --> C(HTTP 403 - CloudFront Level);
    B -- Valid Config --> D{AWS WAF?};
    D -- WAF Rule Block --> E(HTTP 403 - AWS WAF);
    D -- No WAF Block --> F{Origin (S3 / Custom)};
    F -- S3 Bucket Policy / OAC / OAI --> G(HTTP 403 - S3 Access Denied);
    F -- Custom Origin Firewall / SG --> H(HTTP 403 - Origin Network Block);
    F -- Origin App Logic / Auth --> I(HTTP 403 - Custom Origin Logic);
    F -- Object Not Found / Method Not Allowed --> J(HTTP 403 - Origin Resource Issue);
    F -- Successful --> K[Content Delivered];
    C --> L[End User Experience Interrupted];
    E --> L;
    G --> L;
    H --> L;
    I --> L;
    J --> L;
    K --> M[CloudFront to Client];

✅ Verification

After implementing any of the solutions, always verify the fix using the following methods:

1. Direct HTTP Request to CloudFront:

   curl -I https://d123456.cloudfront.net/path/to/object
   

   Expected output: HTTP/2 200 (or 301/302 if redirecting).

2. Verbose HTTP Request for Detailed Headers:

   curl -v https://d123456.cloudfront.net/path/to/object 2>&1 | grep -E '(HTTP|403|Access|x-amz-error|x-cache)'
   

   Look for HTTP/2 200 and x-cache: Hit from cloudfront or x-cache: Miss from cloudfront. Absence of 403 or Access Denied indicates success.

3. Inspect CloudFront Distribution Configuration:

   DIST_ID="D123456ABCDEF" # Replace with your distribution ID
   aws cloudfront get-distribution-config --id "$DIST_ID" --output json | jq '.DistributionConfig | {Origins, DefaultCacheBehavior: {AllowedMethods, ViewerProtocolPolicy}}'
   

   Verify Origins, AllowedMethods, and ViewerProtocolPolicy match your desired configuration.

4. Review S3 Bucket Policy (if applicable):

   aws s3api get-bucket-policy --bucket my-bucket --output json | jq '.Policy | fromjson'
   

   Confirm the bucket policy includes the necessary Allow statement for CloudFront's OAC/OAI.

5. Check AWS WAF Rules (if applicable):

   # Replace with your Web ACL name, ID, and ARN
   WEB_ACL_NAME="my-web-acl"
   WEB_ACL_ID="a1b2c3d4-e5f6-7890-1234-567890abcdef"
   aws wafv2 get-web-acl --name "$WEB_ACL_NAME" --scope CLOUDFRONT --id "$WEB_ACL_ID" --region us-east-1 --output json | jq '.WebACL.Rules'
   

   Ensure no overly restrictive rules are in place.

6. Monitor CloudFront Logs (if enabled):

   # Replace '/aws/cloudfront/my-distribution' with your actual CloudWatch Log Group name
   # This assumes CloudFront logs are sent to CloudWatch Logs.
   aws logs tail /aws/cloudfront/my-distribution --follow 2>/dev/null | grep 403
   

   Confirm that 403 entries are no longer appearing for the problematic requests.

📦 Prerequisites

To effectively troubleshoot and resolve CloudFront 403 errors, ensure you have:

• AWS CLI v2 (latest stable version) installed and configured with appropriate credentials.
• jq for parsing JSON output from AWS CLI.
• curl or wget for HTTP testing.
• IAM permissions for cloudfront:*, s3:*, wafv2:*, and logs:* within the affected AWS account.
• CloudFront distribution ID and S3 bucket name relevant to the issue.
• SSH access to custom origin servers (if applicable).
• Private key for signed URL generation (if using signed URLs).