A flaw in the operating system for Cisco Systems' Catalyst switches could be used to shut down and reset the hardware, the network device maker said in an advisory released Wednesday. The flaw affects the way the CatOS handles Telnet, HTTP (Hypertext Transfer Protocol), and SSH (secure shell) sessions, the advisory said.
Catalyst switches are generally used by corporations with large networks and by Internet service providers. The vulnerability does not affect all versions of the Catalyst series switches. Cisco's router operating system, IOS, is not affected by the bug.