Lexmark encrypts the firmware update packages provided to consumers, making the binary analysis more difficult. With little over a month of research time assigned and few targets to look at, NCC Group decided to remove the flash memory and extract the firmware using a programmer, firmware which we (correctly) assumed would be stored unencrypted. This allowed us to bypass the firmware update package encryption. With the firmware extracted, the binaries could be reverse-engineered to find vulnerabilities that would allow remote code execution.
The Microcontroller Unit (MCU) is the heart of an embedded device, where the main firmware executes its instructions to carry out the system’s functions. These come in many varieties. Relatively simple microcontrollers with limited-resource processors may bundle only a few IO peripherals, a small amount of memory, and be intended to run a small real-time … Continue reading Choosing the Right MCU for Your Embedded Device — Desired Security Features of Microcontrollers
Introduction Internet of Things security can mean any number of things for your product and its users. This will depend largely on the context of the product and its deployment, and can include specific requirements, such as integrity, confidentiality, availability, safety, privacy, consent, authenticity, and more. Understanding how security fits into the product’s threat modelling … Continue reading Why IoT Security Matters