CVE-2020-5681
📋 TL;DR
This CVE describes an untrusted search path vulnerability in self-extracting files created by EpsonNet SetupManager and Offirio SynergyWare PrintDirector. Attackers can place a malicious DLL in a directory that gets searched before legitimate system directories, leading to privilege escalation when the vulnerable software runs. Organizations using these specific Epson printer management tools are affected.
💻 Affected Systems
- EpsonNet SetupManager
- Offirio SynergyWare PrintDirector
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with administrative privileges, allowing attackers to install persistent malware, steal sensitive data, or disrupt operations.
Likely Case
Local privilege escalation enabling attackers to gain higher privileges than their current user account, potentially accessing restricted files or installing additional malware.
If Mitigated
Limited impact with proper application whitelisting and least privilege principles in place, potentially preventing DLL execution or limiting damage.
🎯 Exploit Status
Exploitation requires ability to place malicious DLL in search path and trigger execution of vulnerable self-extracting file.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: EpsonNet SetupManager v2.2.15 or later; Offirio SynergyWare PrintDirector v1.6z or later
Vendor Advisory: https://www.epson.jp/support/misc_t/201217_oshirase.htm
Restart Required: No
Instructions:
1. Download updated versions from Epson support site. 2. Uninstall vulnerable versions. 3. Install patched versions. 4. Regenerate any self-extracting files with updated software.
🔧 Temporary Workarounds
Restrict DLL search paths
windowsUse Windows policies to restrict DLL search order or block loading from untrusted directories
Use Group Policy: Computer Configuration > Windows Settings > Security Settings > Application Control Policies > AppLocker > DLL Rules
Remove vulnerable software
windowsUninstall affected software if not required for operations
Control Panel > Programs and Features > Uninstall EpsonNet SetupManager/PrintDirector
🧯 If You Can't Patch
- Implement strict application whitelisting to prevent execution of unauthorized DLLs
- Run affected software with least privilege accounts and monitor for suspicious DLL loading
🔍 How to Verify
Check if Vulnerable:
Check installed version of EpsonNet SetupManager or Offirio SynergyWare PrintDirector via Control Panel > Programs and FeaturesCheck Version:
wmic product where "name like '%EpsonNet%' or name like '%PrintDirector%'" get name, versionVerify Fix Applied:
Verify installed version is v2.2.15+ for SetupManager or v1.6z+ for PrintDirector, and regenerate any existing self-extracting files📡 Detection & Monitoring
Log Indicators:
- Windows Event Logs showing DLL loading from unusual directories
- Process Monitor logs showing DLL search order hijacking
Network Indicators:
- Not network exploitable - focus on host-based detection
SIEM Query:
EventID=7 OR EventID=11 (DLL loading events) | where DLLPath contains unusual directories AND ProcessName contains 'Epson'