CVE-2022-27041
📋 TL;DR
CVE-2022-27041 is an SQL injection vulnerability in OpenSIS Classic's Student.php module that allows attackers to manipulate the student_id parameter to execute arbitrary SQL queries. This affects all users of OpenSIS Classic 8.0 who have the eligibility module enabled, potentially exposing sensitive student and system data.
💻 Affected Systems
- OpenSIS Classic
📦 What is this software?
Opensis by Os4ed
⚠️ Risk & Real-World Impact
Worst Case
Complete database compromise including extraction of all student records, administrative credentials, and potential remote code execution through database functions.
Likely Case
Unauthorized access to student records, grades, personal information, and potential privilege escalation within the application.
If Mitigated
Limited information disclosure if proper input validation and parameterized queries are implemented.
🎯 Exploit Status
Exploitation requires access to the eligibility module but does not require authentication. The vulnerability is straightforward to exploit using standard SQL injection techniques.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check GitHub repository for latest patched version
Vendor Advisory: https://github.com/OS4ED/openSIS-Classic/issues/248
Restart Required: No
Instructions:
1. Update to the latest version of OpenSIS Classic from the official repository. 2. Apply the patch for Student.php that implements proper input validation and parameterized queries. 3. Verify the fix by testing the student_id parameter.
🔧 Temporary Workarounds
Input Validation Filter
allAdd server-side validation to only accept numeric values for student_id parameter
Add validation in Student.php: if(!is_numeric($_GET['student_id'])) { die('Invalid input'); }
Web Application Firewall Rule
allBlock SQL injection patterns targeting the eligibility module
WAF rule: deny requests to /modules/eligibility/* containing SQL keywords in parameters
🧯 If You Can't Patch
- Disable the /modules/eligibility/ module entirely if not required
- Implement network segmentation to restrict access to OpenSIS application to authorized users only
🔍 How to Verify
Check if Vulnerable:
Test the student_id parameter with SQL injection payloads like: /modules/eligibility/Student.php?student_id=1' OR '1'='1Check Version:
Check OpenSIS version in admin panel or review source code version markersVerify Fix Applied:
Attempt SQL injection after patch and verify error messages or unexpected data are not returned📡 Detection & Monitoring
Log Indicators:
- Unusual SQL error messages in application logs
- Multiple rapid requests to Student.php with varying student_id parameters
- Requests containing SQL keywords (UNION, SELECT, etc.) in student_id parameter
Network Indicators:
- HTTP requests to /modules/eligibility/Student.php with non-numeric student_id values
- Abnormal response sizes from eligibility module queries
SIEM Query:
source="web_logs" AND uri_path="/modules/eligibility/Student.php" AND (query_string="*UNION*" OR query_string="*SELECT*" OR query_string="*OR*1*" OR query_string="*'*'*'*")