CVE-2023-24051
📋 TL;DR
CVE-2023-24051 is a client-side rate limiting vulnerability in Connectize AC21000 G6 routers that allows attackers to bypass authentication controls via brute force attacks. This enables privilege escalation where attackers can gain administrative access to the router. Affected users are those running vulnerable firmware versions of the Connectize AC21000 G6 router.
💻 Affected Systems
- Connectize AC21000 G6 Dual-Band Gigabit WiFi Router
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers gain full administrative control of the router, enabling traffic interception, network compromise, credential theft, and persistent backdoor installation.
Likely Case
Attackers gain administrative access to modify router settings, redirect DNS, or intercept network traffic.
If Mitigated
With proper rate limiting and authentication controls, attackers cannot brute force credentials and the system remains secure.
🎯 Exploit Status
The vulnerability is in client-side rate limiting, making brute force attacks trivial with automated tools.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check with Connectize for updated firmware
Restart Required: Yes
Instructions:
1. Check Connectize website for firmware updates. 2. Download latest firmware. 3. Log into router admin interface. 4. Navigate to firmware update section. 5. Upload and apply new firmware. 6. Reboot router.
🔧 Temporary Workarounds
Disable Remote Admin Access
allPrevent external access to router administration interface
Log into router admin → Security/Admin → Disable 'Remote Management' or 'Remote Access'
Implement Network-Level Rate Limiting
linuxUse firewall or IPS to limit authentication attempts to router
iptables -A INPUT -p tcp --dport 80 -m state --state NEW -m recent --set
iptables -A INPUT -p tcp --dport 80 -m state --state NEW -m recent --update --seconds 60 --hitcount 10 -j DROP
🧯 If You Can't Patch
- Isolate router admin interface to trusted internal network only
- Implement strong, complex passwords and enable account lockout policies if supported
🔍 How to Verify
Check if Vulnerable:
Check router firmware version in admin interface under System/Status or About sectionCheck Version:
Check via web interface: http://router-ip/status or http://router-ip/aboutVerify Fix Applied:
Verify firmware version is newer than 641.139.1.1256 and test authentication rate limiting📡 Detection & Monitoring
Log Indicators:
- Multiple failed login attempts from single IP
- Successful admin login from unusual IP
- Authentication rate exceeding normal thresholds
Network Indicators:
- High volume of HTTP POST requests to login endpoint
- Brute force tool patterns in HTTP headers
SIEM Query:
source="router.log" ("login failed" OR "authentication failure") | stats count by src_ip | where count > 10🔗 References
- https://research.nccgroup.com/2023/10/19/technical-advisory-multiple-vulnerabilities-in-connectize-g6-ac2100-dual-band-gigabit-wifi-router-cve-2023-24046-cve-2023-24047-cve-2023-24048-cve-2023-24049-cve-2023-24050-cve-2023-24051-cve/
- https://research.nccgroup.com/2023/10/19/technical-advisory-multiple-vulnerabilities-in-connectize-g6-ac2100-dual-band-gigabit-wifi-router-cve-2023-24046-cve-2023-24047-cve-2023-24048-cve-2023-24049-cve-2023-24050-cve-2023-24051-cve/
