Security researchers have found a way to use JavaScript to map a home or corporate network and attack connected servers or devices, such as printers or routers.
The malicious JavaScript can be embedded in a Web page and will run without warning when the page is viewed in any ordinary browser, the researchers said. It will bypass security measures such as a firewall because it runs through the user's browser, they said.
"We have discovered a technique to scan a network, fingerprint all the Web-enabled devices found and send attacks or commands to those devices," said Billy Hoffman, lead engineer at Web security specialist SPI Dynamics. "This technique can scan networks protected behind firewalls such as corporate networks."
A successful attack could have significant impact. For example, it could scan your home network, detect a router model and then send it commands to enable wireless networking and turn off all encryption, Hoffman said. Or it could map a corporate network and launch attacks against servers that will appear to come from the inside, he said.
"Your browser can be used to hack internal networks," said Jeremiah Grossman the chief technology officer at Web application security company WhiteHat Security. Both SPI Dynamics and WhiteHat Security came up with the JavaScript-based network scanner at about the same time, he said. The companies plan to talk about their findings at next week's Black Hat security event in Las Vegas.
There have been similar attempts to craft JavaScript-based network scanners, but none as advanced as the SPI Dynamics example, Vaskovich said. "SPI Dynamics deserves credit for a clever attack vector and a solid demonstration of the issue. Their method of fingerprinting servers by checking for default image paths and names is slick."
