Cisco Fixes Security Flaw In Nexus Switches

Cisco has released a patch for an operating system flaw that could leave its Nexus switches open to denial-of-service attacks.

The San Jose, Calif.-based network equipment maker released the fix Wednesday for NX-OS. The affected switch series are the Nexus 1000v, 5000 and 7000.

To exploit the vulnerability, a hacker could modify an IP packet to trigger a DoS attack, according to the U.S. Computer Emergency Readiness Team. The agency issued an advisory recommending that Nexus users install the patch.

NX-OS is the network operating system within Nexus switches. The vulnerability is within the OS' IP stack and "any feature that makes use of the services offered by the IP stack to parse IP packets is affected," Cisco said.

"Successful exploitation of the vulnerability that is described in this advisory may result in a reload of an affected device," the company said. "Repeated exploitation could result in a sustained DoS condition."

Cisco released last September a set of security patches fixing 10 separate vulnerabilities in some of its major software and unified communications products. Among the fixes was one for a DoS vulnerability in the IOS IP Service Level Agreement feature. The flaw was triggered when specially crafted UDP packets were sent to a vulnerable device, Cisco said.