A simple scan for unpublished websites within Yahoo's Internet address space gave an unemployed and bored IT worker access to several of the portal company's internal systems, including root access inside the company firewall, the worker says.
Yahoo URLs provided by the man routed to what appeared to be two unprotected Web-based remote administration consoles for company disk and file storage systems. In a written statement, Yahoo spokesperson Mary Osako acknowledged that the servers shouldn't have been exposed to the Internet, and said the company closed off access on Wednesday. "No user data was compromised," Osako wrote. "Yahoo! takes security across its network very seriously."
It's not the first time Yahoo has had to emphasize how seriously it takes security. In September 2001, hacker Adrian Lamo changed several wire service stories on Yahoo News after finding similar Web-based tools unprotected and accessible from the Internet. "It gratifies me to see they have not lost their consistency in terms of network architecture," says Lamo, who attributes the gaffes to inflexible thinking. "Companies don't look at things that are not normally classified as security vulnerabilities."
In this case, the vulnerable machines, which were not password protected, were a Brocade "Fabric Manager" console, and a controller for a cluster of Network Appliance file servers. Chris Wysopal, director of research and development for AtStake, describes them as typical features on sizable corporate networks, but he says they should be password protected, and should never be reachable from the outside. "It would seem that it would be easy to cause a denial of service by shutting off storage devices," says Wysopal. "It shows that [Yahoo] probably needs be doing some sort of network penetration testing using a scanning tool themselves -- even a basic one."
One of the servers included a "Secure Admin" link that, if clicked, spawned a telnet session that connected back to the computer and dropped the user into a root shell -- granting complete access to the machine, according to one of the people who found the holes.
The unemployed IT worker, speaking on condition of anonymity, said he and a friend discovered the vulnerable machines four months ago, in an abundance of free time brought about by the lingering effects of the dot-com crash. Thirty-two years-old, he admits to some light hacking on other occasions, but says he didn't mess with the Yahoo systems. "I don't want them anymore," he says. "I don't like having that kind of power, and sitting on it and thinking, 'What am I going to do?'"