What the vulnerability does
01Description
The firmware upgrade function in the admin web interface of the Rittal IoT Interface & CMC III Processing Unit devices checks if the patch files are signed before executing the containing run.sh script. The signing process is kind of an HMAC with a long string as key which is hard-coded in the firmware and is freely available for download. This allows crafting malicious "signed" .patch files in order to compromise the device and execute arbitrary code.
