CVE-2025-8831
📋 TL;DR
A stack-based buffer overflow vulnerability in the remote management function of Linksys RE series range extenders allows remote attackers to execute arbitrary code by manipulating the portNumber argument. This affects Linksys RE6250, RE6300, RE6350, RE6500, RE7000, and RE9000 devices with firmware up to August 1, 2025. Attackers can exploit this without authentication to potentially take full control of affected devices.
💻 Affected Systems
- Linksys RE6250
- Linksys RE6300
- Linksys RE6350
- Linksys RE6500
- Linksys RE7000
- Linksys RE9000
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete device compromise, lateral movement into internal networks, persistent backdoor installation, and botnet recruitment.
Likely Case
Device takeover enabling network traffic interception, credential harvesting, and use as pivot point for further attacks.
If Mitigated
Limited impact if devices are isolated from critical networks and remote management is disabled.
🎯 Exploit Status
Proof-of-concept exploit code is publicly available on GitHub. The vulnerability requires no authentication and has straightforward exploitation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not available
Vendor Advisory: Not available - vendor did not respond to disclosure
Restart Required: No
Instructions:
No official patch available. Monitor Linksys security advisories for updates. Consider replacing affected devices if no patch becomes available.
🔧 Temporary Workarounds
Disable Remote Management
allDisable the remote management feature in device web interface to prevent exploitation.
Access device web interface > Administration > Remote Management > Disable
Network Segmentation
allIsolate affected devices in separate VLAN with restricted access to critical networks.
Configure firewall rules to block external access to device management ports (typically 80/443)
🧯 If You Can't Patch
- Immediately disable remote management feature in device settings
- Block external internet access to device management interfaces using firewall rules
- Segment affected devices into isolated network zones
- Monitor for unusual network traffic from affected devices
- Consider replacing with alternative devices if no patch becomes available
🔍 How to Verify
Check if Vulnerable:
Check device firmware version in web interface (Settings > Firmware Update). If version date is 20250801 or earlier, device is vulnerable.Check Version:
Check via web interface or use nmap to identify device model and firmware versionVerify Fix Applied:
No official fix available to verify. Verify remote management is disabled and device is not responding on management ports.📡 Detection & Monitoring
Log Indicators:
- Multiple failed connection attempts to /goform/remoteManagement
- Unusual port scanning activity to device management interface
- Buffer overflow patterns in web server logs
Network Indicators:
- Exploit traffic patterns to portNumber parameter
- Unusual outbound connections from range extenders
- Traffic to known exploit repositories
SIEM Query:
source_ip=* AND dest_port IN (80,443) AND url_path="/goform/remoteManagement" AND http_param="portNumber" AND http_param_length>normal🔗 References
- https://github.com/wudipjq/my_vuln/blob/main/Linksys1/vuln_47/47.md
- https://github.com/wudipjq/my_vuln/blob/main/Linksys1/vuln_47/47.md#poc
- https://vuldb.com/?ctiid.319365
- https://vuldb.com/?id.319365
- https://vuldb.com/?submit.626696
- https://www.linksys.com/
- https://github.com/wudipjq/my_vuln/blob/main/Linksys1/vuln_47/47.md
- https://github.com/wudipjq/my_vuln/blob/main/Linksys1/vuln_47/47.md#poc
