CWE-1326: Missing Immutable Root of Trust in Hardware

CWE-1326: Missing Immutable Root of Trust in Hardware is a Common Weakness Enumeration (CWE) entry maintained by MITRE. A missing immutable root of trust in the hardware results in the ability to bypass secure boot or execute untrusted or adversarial boot code. A System-on-Chip (SoC) implements secure boot by verifying or authenticating signed boot code. The signing of the code is achieved by an entity that the SoC trusts. Before executing the boot code, the SoC verifies that the code or the public key with which the code has been signed has not been tampered with. The other data upon which the SoC depends are system-hardware settings in fuses such as whether "Secure Boot is enabled". These data play a crucial role in establishing a Root of Trust (RoT) to execute secure-boot flows. One of the many ways RoT is achieved is by storing the code and data in memory or fuses. This memory should be immutable, i.e., once the RoT is programmed/provisioned in memory, that memory should be locked and prevented from further programming or writes. If the memory contents (i.e., RoT) are mutable, then an adversary can modify the RoT to execute their choice of code, resulting in a compromised secure boot. Note that, for components like ROM, secure patching/update features should be supported to allow authenticated and authorized updates in the field.

If exploited, CWE-1326 (Missing Immutable Root of Trust in Hardware) it can compromise Authentication and Authorization, leading to outcomes such as Gain Privileges or Assume Identity, Execute Unauthorized Code or Commands and Modify Memory.

Recommended mitigations for CWE-1326 include: When architecting the system, the RoT should be designated for storage in a memory that does not allow further programming/writes. During implementation and test, the RoT memory location should be demonstrated to not allow further programming/writes.

CWE-1326 can be detected using Automated Dynamic Analysis and Architecture or Design Review. Combining automated tooling with manual review typically yields the best coverage.

CWE-1326 commonly affects Not Language-Specific. Note that weaknesses are often language-agnostic patterns, so secure coding practices apply broadly.

A CWE (Common Weakness Enumeration) like CWE-1326 describes a category of software weakness — the underlying flaw type. A CVE (Common Vulnerabilities and Exposures) identifies a specific, real-world vulnerability in a particular product. In short, a CWE is the kind of mistake, and a CVE is an instance of that mistake being found in software.