A critical remote command injection vulnerability in Zyxel EX3510-B0 routers allows unauthenticated attackers to gain full control of the device by sending malicious UPnP requests.

This flaw exists in the Universal Plug and Play (UPnP) function. A remote attacker can send specially crafted UPnP SOAP requests that include shell metacharacters, leading to the execution of arbitrary operating system commands with root privileges.

Full compromise of a gateway router allows attackers to intercept all network traffic, pivot to internal systems, and launch further attacks. With a CVSS score of 9.8, this vulnerability represents a total loss of confidentiality, integrity, and availability for the affected network infrastructure.

Immediate Action: Update the Zyxel EX3510-B0 firmware to the latest patched version provided by the vendor immediately.

Proactive Monitoring: Monitor network traffic for unusual UPnP SOAP requests and check for unauthorized configuration changes on the router.

Compensating Controls: Disable UPnP on the router if it is not strictly necessary for business operations to eliminate the attack vector.

Public Exploit Available: false

This is a critical vulnerability that should be addressed with the highest priority. Administrators must apply the firmware update immediately and should consider disabling UPnP as a general security best practice to reduce the device's attack surface.