CVE-2023-26779
📋 TL;DR
CVE-2023-26779 is a deserialization vulnerability in CleverStupidDog yf-exam version 1.8.0 that allows attackers to execute arbitrary code remotely. This affects all systems running the vulnerable version of this software. Successful exploitation could lead to complete system compromise.
💻 Affected Systems
- CleverStupidDog yf-exam
📦 What is this software?
Yf Exam by Yf Exam Project
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with attacker gaining root/admin privileges, data exfiltration, and persistent backdoor installation.
Likely Case
Remote code execution leading to web server compromise, data theft, and lateral movement within the network.
If Mitigated
Attack prevented through proper input validation and deserialization controls, with only failed exploit attempts logged.
🎯 Exploit Status
Public proof-of-concept code is available, making exploitation straightforward for attackers.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not available
Vendor Advisory: Not available
Restart Required: No
Instructions:
No official patch is available. Consider removing or replacing the vulnerable software.
🔧 Temporary Workarounds
Input Validation Filter
allImplement strict input validation to reject serialized objects in user input
Implement custom input sanitization in application code
Network Segmentation
allIsolate vulnerable systems from critical network segments
Configure firewall rules to restrict access to vulnerable service
🧯 If You Can't Patch
- Remove the vulnerable software from production environments
- Implement strict network access controls and monitor for exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check if yf-exam version 1.8.0 is installed on the systemCheck Version:
Check application configuration files or package manager for version informationVerify Fix Applied:
Verify the vulnerable software has been removed or replaced📡 Detection & Monitoring
Log Indicators:
- Unusual deserialization errors
- Suspicious Java/.NET serialization patterns in logs
- Unexpected process creation
Network Indicators:
- Unusual outbound connections from the application server
- Exploit payload patterns in HTTP requests
SIEM Query:
Search for patterns matching known deserialization exploit payloads in web server logs