Specialists of Sirin Software consider security challenges to rank among the top concerns in the digital world of the early third millennium and embedded systems security is no exception. What is more, for embedded product development, security considerations should become a priority.
Unfortunately, this aspect of embedded system software development is largely paid insufficient attention to. On the contrary, crowding more functionalities into devices whose footprints are getting ever tinier, many an unscrupulous embedded software development engineer tends to neglect sophisticating protection against cyber attacks. Plus, under such an approach, security testing is performed just to check the box.
Why is embedded systems security often overlooked or (worse) intentionally skipped even in the best practices for embedded software development? The myths that circulate in the cyber community are responsible for this disregard. These misconceptions claim that embedded solutions are too small an issue for hackers to attempt security breaches, which excludes embedded devices from the list of vulnerable targets. What such devices need is some elementary cyber protection effected by employing embedded software development tools. And this protection boils down to leveraging adequate encryption and authentication mechanisms.
Any serious embedded software development engineer can debunk these delusions, pinpointing features of embedded solutions that make them inherently insecure.
Embedded Systems Security: Where the Shoe Pinches
What are the weaknesses of embedded systems exploited by cybercriminals?
- Physical accessibility. Having become items of everyday use, the products of embedded system design and development are handled by thousands of people. Naturally, it is next to impossible to control who is using the device at the moment and divine purposes this person may have in mind.
- Connectivity. Being a part of the Internet of Things, embedded solutions are connected to a network, which precludes their being totally isolated or completely turned off.
- Long life cycle. Embedded system software development is oftentimes honed to obtain products for mission-critical employment (for instance, in the defense industry or at power plants). They ought to be long-lived systems whose breach resistance is getting obsolete with each month of their usage. And in 20 years they are likely to turn into primitive ventures security-wise, easy to be tampered with even by fledgling hackers.
- Update reluctance. The previous shortcoming translates into this one. Older software that may have stopped being supported can’t be updated. Some operating systems (like Linux) running in kernel space are non-receptive to patching, so they should be re-installed to make them compliant with new security requirements.
Being aware of these major (and many lesser) vulnerabilities of embedded systems security, threat actors exploit them typically worming their way in via the following bottlenecks.
- Memory buffer inadequacy. Hackers can tamper with the system if specialists responsible for embedded product development failed to install restrictions for a program to access all memory locations through proper configuration of the operating system.
- Buffer overflow. Exploiting the previous critical area by writing slews of data or code to the memory buffer, hackers can easily overwhelm its limits. It enables them to invade adjacent memory addresses and overwrite them, taking control of the system or bringing it down.
- Misuse of input validation. If someone enters a negative value input, unconventional characters in the program, or irregular pathname outside the restricted directory, the system crashes. Or allows access to confidential data, which may be even worse.
- Inappropriate authentication. In case the embedded software development engineer failed to provide a proper authentication mechanism, a threat actor can penetrate the system and wreak havoc within it.
How can all those threats be mitigated?
With an Eye towards Security: The Best Practices for Embedded Software Development
Today, the entire procedure of embedded system design and development is overhauled to meet the imperatives of our time. Instead of implementing security measures into the completed solutions, savvy experts came up with the idea of DevSecOps. Standing for development, security, and operations, this approach presupposes incorporating security efforts throughout the entire cycle of manufacturing – from utilizing security-oriented embedded software development tools through safe code-writing to a protected delivery process. What are the basic practices of DevSecOps?
The Partnership of Software and Hardware
Unassisted software endeavors can’t ensure the total protection of an embedded device. On-chip security capabilities, as well as access control measures, must supplement the efforts of software specialists.
Leveraging HSM and TPM
Hardware Security Module is rightly nicknamed hardware root of trust since it is responsible for the functioning of system-on-a-chip (SoC) elements. The latter enable bulk encryption and decryption of CPU offload and manage keys, allowing the device identifier to serve as a component of trusted device operationality.
Trusted Platform Module authorizes cryptoprocessor to handle cryptographic keys and other sensitive data the device memory contains as well as the attestation of the entire system’s integrity while it is being booted.
Guaranteeing Secure Boot
It can be achieved via either reliance on a public key cryptosystem or symmetric key cryptography. In both cases, a device trust anchor generates a digital signature that helps validate the boot image thus ensuring the safety of the corresponding software.
Another vital acronym in the cybersecurity realm stands for Trusted Execution Environment. Aka hardware security zone, it is a secure area within the main processor where the embedded system software development expert can establish the root of trust. This system effectively acting as a security co-processor enables trusted applications to operate on behalf of the system.
Other security-oriented practices include data-at-rest protection, hardware resource partitioning, software isolation, attack surface curtailment, integrity monitoring, and auditing, etc.
Security of embedded solutions is an issue of pivotal importance in the technologically-driven world of the 21st century. In view of the complexity of the task, the procurement of adequate security measures should be entrusted to top-notch specialists in the field. The seasoned team of Sirin Software can implement embedded systems security projects of any difficulty and deliver the first-rate outcome at a reasonable price.