CVE-2025-8822
📋 TL;DR
A stack-based buffer overflow vulnerability in Linksys WiFi range extenders allows remote attackers to execute arbitrary code by manipulating the opMode parameter. This affects multiple RE series models up to August 1, 2025 firmware. 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 to internal networks, persistent backdoor installation, and botnet recruitment.
Likely Case
Device takeover for credential theft, network reconnaissance, or launching attacks against other devices on the network.
If Mitigated
Limited impact if devices are behind firewalls with strict inbound filtering and network segmentation.
🎯 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: Unknown
Vendor Advisory: None available
Restart Required: Yes
Instructions:
1. Check Linksys support website for firmware updates. 2. If update available, download and install via web interface. 3. Reboot device after installation. Note: No vendor patch is currently known.
🔧 Temporary Workarounds
Disable web administration interface
allPrevent remote access to vulnerable endpoint by disabling web administration
Network segmentation and firewall rules
linuxIsolate range extenders on separate VLANs and block inbound access to port 80/443
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP
🧯 If You Can't Patch
- Segment affected devices on isolated network segments with strict firewall rules
- Monitor for exploitation attempts and unusual network traffic from these devices
🔍 How to Verify
Check if Vulnerable:
Check device firmware version via web interface at http://[device-ip]/ or using admin interface. If version date is 20250801 or earlier, device is vulnerable.Check Version:
curl -s http://[device-ip]/ | grep -i firmware || Check web interface manuallyVerify Fix Applied:
Verify firmware version shows date after 20250801. Test if /goform/setOpMode endpoint still responds with algDisable function.📡 Detection & Monitoring
Log Indicators:
- HTTP POST requests to /goform/setOpMode with opMode parameter
- Unusual process execution or memory errors in device logs
Network Indicators:
- HTTP traffic to device port 80/443 with opMode parameter manipulation
- Unusual outbound connections from range extender
SIEM Query:
source="firewall" dest_port=80 OR dest_port=443 uri_path="/goform/setOpMode" method="POST"🔗 References
- https://github.com/wudipjq/my_vuln/blob/main/Linksys1/vuln_56/56.md
- https://github.com/wudipjq/my_vuln/blob/main/Linksys1/vuln_56/56.md#poc
- https://vuldb.com/?ctiid.319356
- https://vuldb.com/?id.319356
- https://vuldb.com/?submit.626686
- https://www.linksys.com/
- https://github.com/wudipjq/my_vuln/blob/main/Linksys1/vuln_56/56.md
- https://github.com/wudipjq/my_vuln/blob/main/Linksys1/vuln_56/56.md#poc
