The product does not properly handle unexpected physical or environmental conditions that occur naturally or are artificially induced.
Hardware products are typically only guaranteed to behave correctly within certain physical limits or environmental conditions. Such products cannot necessarily control the physical or external conditions to which they are subjected. However, the inability to handle such conditions can undermine a product's security. For example, an unexpected physical or environmental condition may cause the flipping of a bit that is used for an authentication decision. This unexpected condition could occur naturally or be induced artificially by an adversary. Physical or environmental conditions of concern are: - **Atmospheric characteristics: ** extreme temperature ranges, etc. - **Interference: ** electromagnetic interference (EMI), radio frequency interference (RFI), etc. - **Assorted light sources: ** white light, ultra-violet light (UV), lasers, infrared (IR), etc. - **Power variances: ** under-voltages, over-voltages, under-current, over-current, etc. - **Clock variances: ** glitching, overclocking, clock stretching, etc. - **Component aging and degradation** - **Materials manipulation: ** focused ion beams (FIB), etc. - **Exposure to radiation: ** x-rays, cosmic radiation, etc.
In requirements, be specific about expectations for how the product will perform when it exceeds physical and environmental boundary conditions, e.g., by shutting down.
Where possible, include independent components that can detect excess environmental conditions and have the capability to shut down the product.
Where possible, use shielding or other materials that can increase the adversary's workload and reduce the likelihood of being able to successfully trigger a security-related failure.
Consequences of this weakness are highly dependent on the role of affected components within the larger product.