What is the Exposed Service CWMP Vulnerability, what is the risk and how can you mitigate that risk?

In Cyberattacks, Support

What is it?

CPE WAN Management Protocol (CWMP, also known as TR-069) allows a remote computer to manage broadband routers, VoIP phones, etc. If Universal Plug and Play (UPnP) is supported and configured, CWMP can be used to manage devices inside the local area network. By default, CWMP uses ports 7547-7550.

A Man in The Middle (MiTM) attack is when a bad actor takes control of an intermediate device (like a router), using it to listen to (and potentially alter) communications passing through the device.

A Distributed Reflection Denial of Service (DRDoS) attack makes use of a legitimate service to generate large reports, redirecting many of these reports to a victim’s computer in order to overwhelm that computer. By passing through the legitimate service, bad actors can disguise their identity.

Why is it a risk?

Because CWMP provides access inside your network to the Internet at large, CWMP carries a certain amount of risk. The CWMP protocol is, itself, quite secure BUT configurations that do not use TLS or which use default or simple passwords can make your network susceptible to MiTM attacks (eavesdropping) and, for large networks, can be used to overwhelm your network with traffic (a DRDoS attack).

UPnP can provide no-configuration (and no-security) access to devices inside your network such as video cameras, routers and printers. While it is sometimes useful to access these devices across the Internet, unrestricted access creates a security risk.

How can you mitigate the risk?

The QA Cafe link below provides excellent advice regarding securing your CWMP installation.

An important part of mitigating this threat is to restrict access to UPnP devices. The Fastest VPN link below explains UPnP and describes best practices for making UPnP less vulnerable.