CVE-2026-0774
📋 TL;DR
This vulnerability allows network-adjacent attackers to execute arbitrary code on WatchYourLAN installations without authentication. Attackers can inject malicious arguments through the arpstrs parameter, leading to remote code execution as the service account. Only systems running vulnerable versions of WatchYourLAN are affected.
💻 Affected Systems
- WatchYourLAN
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise allowing attackers to install persistent backdoors, steal sensitive network data, pivot to other systems, or disrupt network operations.
Likely Case
Attackers gain initial foothold on the network, potentially escalating privileges and moving laterally to compromise other systems.
If Mitigated
Attack is blocked at network perimeter, limiting impact to isolated network segment with no critical systems.
🎯 Exploit Status
No authentication required. Simple argument injection leads to RCE. ZDI advisory suggests exploit is straightforward.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check vendor advisory for specific version
Vendor Advisory: https://www.zerodayinitiative.com/advisories/ZDI-26-039/
Restart Required: Yes
Instructions:
1. Check current WatchYourLAN version. 2. Update to patched version from official repository. 3. Restart WatchYourLAN service. 4. Verify fix is applied.
🔧 Temporary Workarounds
Network Segmentation
linuxRestrict access to WatchYourLAN configuration page to trusted management networks only
iptables -A INPUT -p tcp --dport [WATCHYOURLAN_PORT] -s [TRUSTED_NETWORK] -j ACCEPT
iptables -A INPUT -p tcp --dport [WATCHYOURLAN_PORT] -j DROP
Disable Configuration Page
linuxTemporarily disable the vulnerable configuration interface if not needed
systemctl stop watchyourlan
comment out or remove configuration page settings in watchyourlan config
🧯 If You Can't Patch
- Isolate WatchYourLAN system on separate VLAN with strict access controls
- Implement network-based intrusion prevention system (IPS) rules to block exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check if WatchYourLAN is running and accessible from network-adjacent systems. Review version against patched releases.Check Version:
watchyourlan --version or check package manager: dpkg -l | grep watchyourlan or rpm -qa | grep watchyourlanVerify Fix Applied:
After patching, attempt to access configuration page and verify proper input validation. Check service logs for any exploitation attempts.📡 Detection & Monitoring
Log Indicators:
- Unusual command execution in WatchYourLAN logs
- Multiple failed or suspicious requests to configuration page
- Unexpected system commands originating from WatchYourLAN process
Network Indicators:
- Unusual network traffic to/from WatchYourLAN port
- Suspicious payloads in HTTP requests to configuration endpoint
- Network connections from WatchYourLAN to unexpected destinations
SIEM Query:
source="watchyourlan.log" AND (arpstrs="*;*" OR arpstrs="*|*" OR arpstrs="*`*" OR arpstrs="*$(*")