Zero-Day Advisory

Fortinet Discovers Netgear R8500 Stack Buffer Overflow in CGI Handler


Fortinet's FortiGuard Labs has discovered multiple stack-based buffer overflows in Netgear NightHawk routers.

Netgear is a global computer networking company based in San Jose, California, in the United States. It produces networking hardware for consumers, businesses, and service providers

There is stack buffer overflow issue in wlg_adv.cgi CGI handler. The CGI handler does not assess the length of the device name sent via HTTP request.


FortiGuard Labs released the following FortiGate IPS signature which covers this specific vulnerability:

Released May 14, 2018
Users should apply latest update from the vendor


Fortinet reported the vulnerability to Netgear on 17, April 2018

Netgear confirmed the vulnerability on 26, April 2018

Netgear released patch for the vulnerability on 04, September 2019


This vulnerability was discovered by Wayne Low of Fortinet's FortiGuard Labs.

IPS Subscription

Fortinet customers who subscribe to Fortinet's intrusion prevention (IPS) service should be protected against this vulnerability with the appropriate configuration parameters in place. Fortinet's IPS service is one component of FortiGuard Subscription Services, which also offer comprehensive solutions such as antivirus, Web content filtering and antispam capabilities. These services enable protection against threats on both application and network layers. FortiGuard Services are continuously updated by FortiGuard Labs, which enables Fortinet to deliver a combination of multi-layered security intelligence and true zero-day protection from new and emerging threats. These updates are delivered to all FortiGate, FortiMail and FortiClient products. Fortinet strictly follows responsible disclosure guidelines to ensure optimum protection during a threat's lifecycle.