Cisco issued four updates that patch a raft of security holes in products running its Internetwork Operating System (IOS). Impacts included sustained denial of service attacks, data leakage and remote execution of code.
The most serious vulnerabilities reside in voice-enabled devices and Cisco Unified Communications Manager, which can allow an attacker to remotely execute malicious code. There are no workarounds for the flaws, which pertain to services such as Session Initiation Protocol, Media Gateway Control Protocol, Signaling protocols H.323, H.254, Real-time Transport Protocol and Facsimile reception.
"This one is bad, as in real bad," Johannes Ullrich, CTO for SANS Internet Storm Center, told The Reg. "I would probably expedite the testing process for that. "The other vulnerabilities, you want to be really careful about testing them and they don't seem to be overly critical."
Vulnerable IOS versions include various flavors of 12.3(4), 12.3(7), 12.3(8), 12.4 Mainline and 12.4T onward. Routers that are configured as SIP Public Switched Telephone Network Gateways and SIP Session Border Controllers are also vulnerable, as is the CAT6000-CMM card.
Other updates addressed a data leakage flaw when using IPv6 routing headers and a weakness in the IOS Next Hop Resolution Protocol that can result in a restart of the device or possible remote code execution.
A fourth patch plugs a hole in some 12.2-based IOS releases when configured to offer Secure Copy server functionality. Those vulnerabilities allow valid users, regardless of privilege level, to transfer files to and from an IOS device. To exploit it, an attacker would have to have access to port 22, which typically is open only on management interfaces.
Nonetheless, Immunity, a company that provides penetration testing tools, plans to add modules to its products that test for the vulnerability, said Kostya Kortchinsky, a senior researcher at the company.
"Anybody can exploit this without any skill in Cisco exploitation," he explained. "It doesn't need any overflow of any kind."
The patches were released the same day Cisco's website was inaccessible for about three hours. A spokeswoman later said the outage was the result of an accident during maintenance that cut off power to a San Jose data center. ®