Learn how to fix AWS’s “Failed to Refresh Cached Credentials” error. Our AWS Support team is here to help you with your questions and concerns.

How to Fix the “Failed to Refresh Cached Credentials” Error in AWS

One of our customers recently had trouble with the “failed to refresh cached credentials” error message.

This error indicates a disruption in retrieving or renewing authentication credentials. This can affect access to AWS services through the CLI, SDKs, or other integrations.

Today, we will break down the causes, operational impacts, and step-by-step solutions for this error.

According to our Experts, this error usually occurs when AWS tools can’t refresh the cached credentials required for authentication. It often appears in setups using temporary security credentials, IAM roles, or federated identity providers.

If you manage credentials in dynamic environments like ElastiCache for Redis, this issue could also affect your ability to manage or persist in-memory data. Learn more about Redis persistence in AWS ElastiCache.

Key Impacts of the Error

• Blocks access to AWS services and APIs.
• Interrupts ongoing workflows and automation.
• Prevents programmatic operations and deployments.
• Stops AWS CLI commands from running.
• Halts automated scripts and CI/CD pipelines.
• Can lead to downtime in critical systems.
• It may cause unauthorized access attempts due to misconfigured fallbacks.
• Disrupts audit trails and compliance checks.
• Affects secure application operation.
• Introduces delays and timeouts in cloud operations.
• Requires manual recovery efforts.
• Slows down distributed services.
• Fails to launch or manage EC2 instances.
• Blocks access to S3, EKS, and other AWS resources.
• Interrupts container deployments and infrastructure updates.

If your organization manages multiple IAM users, keeping credentials clean and up to date is essential. Learn how to automate IAM user cleanup to reduce clutter and risk in your AWS account.

Root Causes and How to Fix Them

1. Expired Temporary Credentials

The session token has expired.

2. Misconfigured Credential Provider Chain

Incorrect settings in the AWS CLI or SDK credential chain.

3. Missing IAM Role on EC2 Instances

The EC2 instance lacks an attached IAM role, or the role lacks permissions.

4. Network or Connectivity Issues

Network problems prevent communication with AWS endpoints.

from botocore.config import Config
import boto3
retry_config = Config(retries={'max_attempts': 5, 'mode': 'adaptive'})
client = boto3.client('s3', config=retry_config)
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5. Token Refresh Mechanism Failure

Custom identity providers fail to refresh tokens correctly.

class CustomCredentialProvider:
def refresh_credentials(self):
try:
return self.get_new_credentials()
except Exception as e:
logging.error(f"Credential refresh failed: {e}")
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6. Incorrect Credential Process Configuration

Misconfigured external credential processes are returning invalid JSON.

{
"Version": 1,
"AccessKeyId": "ACCESS_KEY",
"SecretAccessKey": "SECRET_KEY",
"Expiration": "ISO_8601_TIMESTAMP"
}
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7. Multi-Factor Authentication (MFA) Issues

MFA requirements break the credential refresh workflow.

def refresh_mfa_credentials():
mfa_token = get_mfa_token()
sts = boto3.client('sts')
credentials = sts.get_session_token(
DurationSeconds=43200,
SerialNumber='MFA_DEVICE_ARN',
TokenCode=mfa_token
)
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Prevention Strategies

• Use IAM roles over long-term access keys.
• Rotate credentials automatically.
• Also, use STS for temporary credentials.
• Use AWS SDK’s built-in credential chains.
• Test fallback providers.
• Additionally, create independent refresh scripts.
• Use CloudWatch to alert on auth failures.
• Furthermore, log credential usage.
• Audit IAM role usage regularly.
• Regularly rotate long-term credentials.
• Also, avoid hardcoded secrets.
• Use MFA and conditional policies.

AWS services like ElastiCache also benefit from secure configuration. You can take additional steps by enabling encryption for Amazon ElastiCache for Redis to keep your data protected even when authentication mechanisms fail.

[Need assistance with a different issue? Our team is available 24/7.]

Conclusion

The “failed to refresh cached credentials” error may initially seem minor but can lead to serious issues. We can keep our AWS environment secure by understanding its root causes and implementing the right fix.

In brief, our Support Experts demonstrated how to fix AWS’s “Failed to Refresh Cached Credentials” Error.