CVE-2025-0693
📋 TL;DR
This vulnerability in AWS Sign-in allows attackers to use timing differences in IAM user login responses to brute-force enumerate valid usernames in AWS accounts. Any AWS account using IAM users for authentication is potentially affected. This enables reconnaissance that can lead to credential attacks.
💻 Affected Systems
- AWS Identity and Access Management (IAM)
⚠️ 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
Attackers identify all valid IAM usernames in an AWS account, enabling targeted phishing, credential stuffing, or brute-force password attacks against known valid accounts.
Likely Case
Attackers enumerate some valid usernames and use them for targeted credential attacks or reconnaissance to understand organizational structure.
If Mitigated
With MFA, strong passwords, and account lockout policies, impact is limited to username disclosure without access.
🎯 Exploit Status
Exploitation requires only network access to AWS Sign-in endpoints and basic scripting capabilities.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: AWS backend fix - no customer action required
Vendor Advisory: https://aws.amazon.com/security/security-bulletins/AWS-2025-002/
Restart Required: No
Instructions:
1. AWS has deployed fixes on their backend. 2. No customer action required for the core vulnerability. 3. Review IAM security best practices.
🔧 Temporary Workarounds
Enable IAM password policies
allImplement strong password policies and account lockout to mitigate credential attacks following username enumeration
aws iam update-account-password-policy --minimum-password-length 14 --require-symbols --require-numbers --require-uppercase-characters --require-lowercase-characters --allow-users-to-change-password --max-password-age 90 --password-reuse-prevention 24 --hard-expiry
Enable MFA for all IAM users
allRequire multi-factor authentication for all IAM users to prevent credential-based attacks
aws iam create-virtual-mfa-device --virtual-mfa-device-name MyMFADevice --outfile QRCode.png --bootstrap-method QRCodePNG
🧯 If You Can't Patch
- Implement AWS WAF rules to detect and block rapid login attempts
- Monitor CloudTrail logs for unusual authentication patterns and failed login attempts
🔍 How to Verify
Check if Vulnerable:
Check AWS security bulletin for confirmation of fix deployment in your regionCheck Version:
N/A - Cloud service fixVerify Fix Applied:
AWS has applied fixes globally - verify by checking the security bulletin status📡 Detection & Monitoring
Log Indicators:
- Unusual patterns of failed sign-in attempts in AWS CloudTrail
- Multiple authentication attempts from single IPs against different usernames
Network Indicators:
- High volume of requests to signin.aws.amazon.com from single sources
- Patterned username guessing attempts
SIEM Query:
source="aws.cloudtrail" eventName="ConsoleLogin" errorMessage="Invalid username or password" | stats count by userIdentity.userName, sourceIPAddress