CVE-2023-51646
📋 TL;DR
This vulnerability allows authenticated remote attackers to bypass authentication and execute arbitrary code on Allegra installations via directory traversal in the uploadSimpleFile method. Attackers can achieve remote code execution in the LOCAL SERVICE context. Organizations using vulnerable Allegra versions are affected.
💻 Affected Systems
- Allegra
📦 What is this software?
Allegra by Alltena
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise through remote code execution with LOCAL SERVICE privileges, potentially leading to lateral movement, data exfiltration, or ransomware deployment.
Likely Case
Unauthorized file upload leading to web shell deployment, data manipulation, or service disruption.
If Mitigated
Limited impact due to network segmentation, strong authentication controls, and file integrity monitoring preventing successful exploitation.
🎯 Exploit Status
Authentication bypass mechanism exists, making exploitation easier for attackers with some access. ZDI-CAN-22527 tracking suggests active research interest.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 7.5.1
Vendor Advisory: https://www.trackplus.com/en/service/release-notes-reader/7-5-1-release-notes-2.html
Restart Required: Yes
Instructions:
1. Download Allegra version 7.5.1 from official vendor sources. 2. Backup current installation and configuration. 3. Apply the update following vendor documentation. 4. Restart Allegra services. 5. Verify successful update and functionality.
🔧 Temporary Workarounds
Restrict File Upload Paths
windowsConfigure Allegra to only allow file uploads to specific, non-executable directories with strict permissions.
Network Segmentation
allIsolate Allegra servers from critical systems and restrict inbound access to authenticated users only.
🧯 If You Can't Patch
- Implement strict network access controls to limit Allegra server exposure
- Deploy web application firewall (WAF) rules to block directory traversal patterns
🔍 How to Verify
Check if Vulnerable:
Check Allegra version in administration panel or via installed program details in Windows. Versions below 7.5.1 are vulnerable.Check Version:
Check Allegra web interface → Administration → System Information or Windows Programs and FeaturesVerify Fix Applied:
Confirm version is 7.5.1 or higher in administration interface and test file upload functionality with traversal attempts.📡 Detection & Monitoring
Log Indicators:
- Unusual file upload patterns
- Directory traversal strings in request logs
- Authentication bypass attempts
- Unexpected process execution from Allegra directories
Network Indicators:
- HTTP requests containing '../' patterns to upload endpoints
- Unusual outbound connections from Allegra server
SIEM Query:
source="allegra_logs" AND (http_uri="*../*" OR http_method="POST" AND http_uri="*upload*")