CVE-2023-42495
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary operating system commands on Dasan Networks W-Web devices through improper input sanitization. Attackers can gain complete control of affected devices running versions 1.22 through 1.27. Organizations using these specific Dasan Networks products are at risk.
💻 Affected Systems
- Dasan Networks W-Web
📦 What is this software?
W Web by Dasannetworks
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attackers to install persistent backdoors, exfiltrate sensitive data, pivot to internal networks, or render devices inoperable.
Likely Case
Remote code execution leading to device takeover, credential theft, network reconnaissance, and potential lateral movement within the network.
If Mitigated
Limited impact if devices are behind firewalls with strict inbound filtering and network segmentation prevents lateral movement.
🎯 Exploit Status
OS command injection vulnerabilities typically have low exploitation complexity. Given the high CVSS score and public advisory, weaponization is likely even without public PoC.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version 1.28 or later
Vendor Advisory: https://www.gov.il/en/Departments/faq/cve_advisories
Restart Required: Yes
Instructions:
1. Download latest firmware from Dasan Networks support portal. 2. Backup current configuration. 3. Apply firmware update via web interface or CLI. 4. Reboot device. 5. Verify version is 1.28 or higher.
🔧 Temporary Workarounds
Network Access Control
allRestrict network access to W-Web devices using firewall rules
Input Validation Proxy
allDeploy WAF or reverse proxy with command injection protection rules
🧯 If You Can't Patch
- Isolate affected devices in separate VLAN with strict firewall rules allowing only necessary traffic
- Implement network segmentation to prevent lateral movement from compromised devices
🔍 How to Verify
Check if Vulnerable:
Check web interface or CLI for firmware version. If version is between 1.22 and 1.27 inclusive, device is vulnerable.Check Version:
show versionVerify Fix Applied:
Confirm firmware version is 1.28 or higher via web interface or CLI command 'show version'📡 Detection & Monitoring
Log Indicators:
- Unusual command execution in system logs
- Multiple failed authentication attempts followed by successful access
- Suspicious process creation from web service
Network Indicators:
- Unusual outbound connections from W-Web devices
- Traffic to unexpected ports or IP addresses
- Large data exfiltration from device
SIEM Query:
source="dasan-web" AND (event_type="command_execution" OR process_name=*sh* OR cmdline=*bash*)