If you’re using AWS services in your development workflow, there’s a very real chance you’ve either accidentally committed credentials to a public repository or you’re about to. It’s one of those mistakes that feels almost inevitable in modern development, and the consequences can range from embarrassing to financially devastating. The good news is that preventing these leaks isn’t particularly complicated—it just requires awareness and a few systematic habits.
Why This Matters More Than You Think
When AWS credentials end up in a public GitHub repository, they’re usually discovered within minutes. Automated bots constantly scan public repos looking for exactly this kind of leak. I’ve seen cases where malicious actors spun up hundreds of EC2 instances within an hour of credentials being exposed. One developer I know woke up to a $50,000 AWS bill because their access keys sat in a public repo overnight.
The problem isn’t just about cost. Exposed credentials can give attackers access to your databases, customer data, and entire infrastructure. Even if you catch it quickly, you’re looking at a mandatory security incident report, credential rotation across your team, and the uncomfortable conversation with your CTO about how it happened.
Never Store Credentials Directly in Code
This should go without saying, but it’s worth repeating because it’s still the most common mistake. Never hardcode AWS access keys, secret keys, or session tokens directly into your application code. Not in configuration files, not in scripts, not even in comments ”for reference.”
Use environment variables or dedicated secret management tools instead. On your development machine, store credentials in ~/.aws/credentials and reference them through the AWS SDK. The SDK knows how to find and use these credentials without you ever typing them into your codebase.
For production environments, use IAM roles attached to your EC2 instances or ECS tasks. This eliminates the need to manage long-term credentials entirely. Your application automatically receives temporary credentials that rotate regularly.
Set Up Git Hooks and Pre-Commit Checks
Prevention is always better than detection after the fact. Install a pre-commit hook that scans your code for potential secrets before they ever reach your repository. Tools like git-secrets (made by AWS) or detect-secrets can catch common patterns of AWS credentials and block the commit.
Here’s a practical approach: install git-secrets across your entire team and configure it to scan for AWS patterns. It takes about five minutes to set up and will save you from most accidental leaks. Yes, it might occasionally flag false positives, but that’s infinitely better than the alternative.
I’ve made it a standard practice to run these checks on every repository I work with. It’s saved me at least twice from committing API keys that would have been exposed instantly.
Use .gitignore Aggressively
Your .gitignore file should explicitly exclude common locations where credentials might live. Add patterns like .env, *.pem, *.key, and any configuration files that might contain secrets. But don’t stop there—think about your specific workflow and what files might inadvertently contain sensitive data.
Remember that .gitignore only prevents new files from being tracked. If you’ve already committed a credentials file in the past, adding it to .gitignore won’t remove it from your repository history. You’ll need to purge it completely, which brings us to the next point.
What to Do If You’ve Already Leaked Credentials
If you discover that AWS credentials have been committed to a public repository, act immediately. First, rotate the credentials through the AWS console. Disable the exposed access key and generate new ones. Don’t wait to clean up the repository first—assume the credentials are already compromised.
Next, you need to remove the credentials from your repository history. Simply deleting the file in a new commit isn’t enough because the credentials remain in your git history. Use tools like git filter-branch or BFG Repo-Cleaner to scrub the credentials from every commit. This is tedious but necessary.
Finally, check your AWS CloudTrail logs to see if the compromised credentials were used. Look for unusual activity, especially EC2 launches in regions you don’t typically use or API calls you don’t recognize.
Monitor for Accidental Exposures
Even with all these precautions, mistakes happen. That’s where monitoring services come in. Services like LeakVigil continuously scan public repositories and other sources to detect if your organization’s credentials or sensitive data have been exposed. Getting an alert within minutes of a leak can be the difference between a minor incident and a major breach.
GitHub itself also has secret scanning enabled for public repositories, and they’ll notify you if they detect AWS credentials. Don’t ignore these notifications—treat them as the emergencies they are.
Train Your Team on Security Practices
Individual developers can follow best practices perfectly, but if your team doesn’t have a shared understanding of credential security, leaks will happen. Make credential management part of your onboarding process. Review your security policies regularly, especially when new team members join or when you adopt new tools.
Create a clear incident response plan so everyone knows exactly what to do if credentials are exposed. The faster you can respond, the less damage can occur.
Common Misconceptions About Credential Security
One myth I hear frequently is that private repositories are safe for storing credentials. While they’re certainly better than public ones, they’re not a security measure. Private repos can become public accidentally, employees leave companies, and repository access is often broader than you think. Treat private repositories with the same security standards.
Another misconception is that deleting a public repository removes the risk. Unfortunately, others may have already forked your repository or scraped its contents. Once credentials are public, assume they’re compromised permanently.
Questions People Ask About AWS Credential Security
How quickly are exposed credentials discovered? Usually within minutes. Automated scanners are constantly watching public repositories.
Can I just delete the commit with credentials? No, the credentials remain in git history. You need to rewrite the entire repository history.
Are temporary credentials safer? Yes, significantly. They expire automatically and limit the window of potential abuse.
Should I use different credentials for each project? Absolutely. Use separate IAM users or roles with minimal necessary permissions for each project.
The key to preventing AWS credential leaks is building multiple layers of protection. No single measure is perfect, but together they create a system where accidental exposures become rare and quickly caught when they do occur.