Recently a local privilege escalation vulnerability was found in Cisco’s VPN Client. When Cisco VPN Client is installed, a windows service “Cisco Systems, Inc. VPN Service” is created. The service runs the binary C:\Program Files\Cisco Systems\VPN Client\cvpnd.exe as Local System. Therefore, if you replace cvpnd.exe with another executable, then that program will be ran at startup with root privileges! I fond this vulnerability interesting because it is used at my college to authenticate students when they connect to the wireless network. For that reason, almost every student with a laptop has this software installed, and students are allowed to borrow school laptops from the student center to use the wireless internet. Consequently, anyone could borrow a laptop, gain root access thought the vulnerability, and install a keylogger that sends every keystroke to the attacker’s email! Its been 5 days seen this vulnerability was discovered, and Cisco has already issued a patched version. However, how long will it take for the school to update all their computers? This is just another reason why you should be careful when using school computers!

Video Demonstration: (shows how to gain root access and change the Admin password with this vulnerability)

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