Recent high-profile attacks on the Internet of Things (IoT) have brought to the forefront the vulnerability of "smart" devices, and have resulted in IoT technologies and devices being subjected to numerous security analyses. Many of the attacks had weak device configuration as the root cause, making the configuration of IoT devices a vector of interest for security analysis. One potential source of rich and definitive information about the configuration of an IoT device is the device's firmware itself. However, firmware analysis is complex and automated firmware analyses have thus far been confined to IoT hub or gateway devices, or peripheral devices with more traditional operating systems such as Linux or VxWorks. Most IoT peripherals, by their very nature of being resource-constrained, lacking traditional operating systems and implementing a wide variety of communication technologies, have only been the subject of smaller-scale analyses, typically confined to a certain class or brand of device. Analysing peripheral firmware is further complicated by the fact that peripheral firmware files are predominantly available as stripped binaries, without the ELF headers and symbol tables that would simplify reverse engineering.In this paper, we present argXtract, an open-source automated static analysis tool, which extracts security-relevant configuration information from stripped IoT peripheral firmware. Specifically, we target binaries that implement the ARM Cortex-M architecture, due to its growing popularity among IoT peripherals. argXtract overcomes the challenges associated with stripped Cortex-M analysis and is able to retrieve and process arguments to security-relevant supervisor and function calls, enabling automated bulk analysis of firmware files. We demonstrate this via three real-world case studies. The largest case study covers a dataset of 243 Bluetooth Low Energy binaries targeting Nordic Semiconductor chipsets, while the other two focus on Nordic ANT binaries and STMicroelectronics BlueNRG binaries. The results from all three case studies reveal widespread lack of security and privacy controls in IoT, such as minimal or no protection for data, fixed passkeys and trackable device addresses.