Entries tagged “#Reverse”

In this post, I will show you how I bypassed a noexec permission in a limited chrooted env.

A bit of history A few months back, I turned my attention on my fiber gateway. So I ordered the same model on ebay, unsoldered and dump the nand, and after a lot of work, managed to have a clear view of the system, from bootloader to userland. Basically, the bootloader check the signature of the kernel image, uncrypt the kernel image with a bootloader stored key, which in turn, uncrypt the rootfs image and voila. [YYYY] / # ls README dev lib opt sbin usr bin etc media proc sys var config exports mnt root tftpboot ctmp home nonexisting run tm [YYYY] / # cat README If you can read this, congratulations ! Feel free to drop me an email, xxxx@yyyy.zz

The percello prc6000, also known as bcm61650 after Broadcom bought the company, is a chip used in 3g femtocells (Home-nodeB). Here is a summary writeup of how I achieved to bypass its secure ROM to run arbitrary firmwares.

After some time spent, I've finally managed to identify the jtag pins on my MC9620 "phone".