eEye Digital Security, an Aliso Viejo, Calif.-based security firm, issued an advisory on the vulnerability Monday. The company had notified D-Link about the flaw in February.
The vulnerability affects the Local Area Network (LAN) interface of several of D-Link's consumer-grade routers, and a company spokesperson said the Fountain Valley, Calif.-based networking vendor has released patches for download on its Web site.
Mike Puterbaugh, vice president of marketing at eEye, said the vulnerability is serious given the widespread use of D-Link routers in small-business and home networks. "The footprint of D-Link's install base is significant, and this could have potentially turned into a big issue," he said.
eEye rated the severity of the flaw as "high." Danish security firm Secunia rated the vulnerability "moderately critical", and Symantec gave the flaw a "10," its highest severity rating.
Attackers could exploit the vulnerability by sending an excessively long M-search string to a device, triggering a stack-based buffer overflow. M-search commands are sent by devices attempting to connect to Universal Plug and Play (UPnP) networks to find other devices on the network, eEye said.
If successful, attackers could gain the ability to execute arbitrary code and apply modified firmware that could eventually allow them to compromise the whole network, according to eEye.
However, attackers would have to have users' wireless settings or administrator password to exploit the flaw, which causes the router to reboot but doesn't create a denial-of-service situation, the D-Link spokesperson said.