CVE-2025-14764
📋 TL;DR
This vulnerability in the Amazon S3 Encryption Client for Go allows attackers with write access to an S3 bucket to manipulate encrypted data keys, potentially causing decryption to produce different plaintext than originally encrypted. It affects users of the S3 Encryption Client for Go who store encrypted data keys in instruction files rather than S3 metadata. The issue stems from missing cryptographic key commitment.
💻 Affected Systems
- Amazon S3 Encryption Client for Go
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
An attacker with write access could replace encrypted data keys, causing legitimate users to decrypt manipulated data while appearing to use valid encryption, potentially leading to data corruption or malicious content injection.
Likely Case
Inadvertent data corruption if multiple users with write access modify encrypted objects without proper coordination, resulting in inconsistent decryption outcomes.
If Mitigated
With proper access controls limiting write permissions and monitoring for unauthorized modifications, the risk is reduced to accidental data inconsistencies among authorized users.
🎯 Exploit Status
Exploitation requires write access to the S3 bucket and knowledge of the encryption setup using instruction files.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 4.0.0
Vendor Advisory: https://aws.amazon.com/security/security-bulletins/AWS-2025-032/
Restart Required: No
Instructions:
1. Update go.mod to require github.com/aws/amazon-s3-encryption-client-go v4.0.0 or later. 2. Run 'go mod tidy' to update dependencies. 3. Rebuild and redeploy your application.
🔧 Temporary Workarounds
Use S3 metadata for encrypted data keys
allConfigure the S3 Encryption Client to store encrypted data keys in S3 object metadata instead of instruction files, as the vulnerability only affects instruction file storage.
🧯 If You Can't Patch
- Implement strict IAM policies to limit write access to S3 buckets containing encrypted data.
- Enable S3 bucket versioning and monitor for unexpected object modifications.
🔍 How to Verify
Check if Vulnerable:
Check your go.mod file for 'github.com/aws/amazon-s3-encryption-client-go' with version below 4.0.0, and verify if your application uses instruction files for encrypted data keys.Check Version:
grep 'github.com/aws/amazon-s3-encryption-client-go' go.modVerify Fix Applied:
Confirm go.mod specifies version 4.0.0 or later of github.com/aws/amazon-s3-encryption-client-go, and test encryption/decryption with instruction files to ensure consistency.📡 Detection & Monitoring
Log Indicators:
- AWS CloudTrail logs showing unexpected PutObject or similar write operations to S3 buckets containing encrypted data with instruction files.
Network Indicators:
- Unusual patterns of S3 API calls modifying encrypted objects from unauthorized sources.
SIEM Query:
source="aws.cloudtrail" eventName IN ("PutObject", "CopyObject") AND requestParameters.bucketName="your-bucket-name" AND errorCode IS NULL | stats count by userIdentity.arn