CVE-2025-48372
📋 TL;DR
This vulnerability in the Schule school management system allows attackers to brute-force 4-digit OTP codes due to the limited keyspace of only 9000 possible combinations. Attackers could bypass authentication mechanisms and gain unauthorized access to sensitive student and administrative data. All users running Schule versions before 1.0.1 are affected.
💻 Affected Systems
- Schule School Management System
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise where attackers gain administrative access, modify student records, access sensitive personal information, and potentially disrupt school operations.
Likely Case
Unauthorized access to user accounts leading to data theft, privilege escalation, and manipulation of school records.
If Mitigated
Limited impact with proper rate-limiting and account lockout mechanisms in place, though OTPs remain predictable.
🎯 Exploit Status
Exploitation requires access to OTP authentication endpoints; simple brute-force scripts can be created with minimal technical skill.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.0.1
Vendor Advisory: https://github.com/schule111/Schule/security/advisories/GHSA-6c48-67xx-vqgc
Restart Required: Yes
Instructions:
1. Backup current Schule installation and database. 2. Download version 1.0.1 from the official repository. 3. Replace existing files with new version. 4. Restart the web server/service. 5. Verify OTP generation now produces longer, more secure codes.
🔧 Temporary Workarounds
Implement Rate Limiting
allAdd strict rate limiting on OTP verification endpoints to prevent brute-force attempts
# Configure web server rate limiting (nginx example)
limit_req_zone $binary_remote_addr zone=otp:10m rate=5r/m;
location /verify-otp { limit_req zone=otp burst=10 nodelay; }
Add Account Lockout
allImplement account lockout after failed OTP attempts
# Add to authentication logic
if (failed_attempts[$user] >= 5) { lock_account($user, 15); }
🧯 If You Can't Patch
- Implement network-level controls: Restrict access to OTP endpoints using firewalls or WAF rules
- Enable comprehensive logging and monitoring of OTP authentication attempts for detection
🔍 How to Verify
Check if Vulnerable:
Check if generateOTP() function produces 4-digit codes (1000-9999) by examining source code or testing OTP generationCheck Version:
Check Schule version in admin panel or examine package.json/composer.json for version numberVerify Fix Applied:
Verify OTP codes are longer than 4 digits and include alphanumeric characters after upgrading to 1.0.1📡 Detection & Monitoring
Log Indicators:
- Multiple failed OTP verification attempts from single IP/user
- Unusual pattern of OTP requests (e.g., sequential attempts)
Network Indicators:
- High volume of requests to /verify-otp or similar endpoints
- Pattern of requests with incrementing 4-digit values
SIEM Query:
source="schule_logs" (url="/verify-otp" OR url="/authenticate") | stats count by src_ip, user | where count > 10