Hardware roots of trust can be used to support many desirable device security functions, such as secure key and secret storage, secure boot, and firmware integrity measurement. These functions often rely on the root of trust being immutable, preventing a threat actor from making changes to code or data in the root of trust that would undermine the security functions built atop them. However, if the root of trust implementation is flawed, immutability prevents the revocation and replacement of compromised keys, and prevents patching vulnerable code. Therefore, if threat actors have access to a mechanism to obtain the secret data or code, and/or those secrets and code are shared over multiple devices and threat actors can obtain them, then devices will remain vulnerable past threat disclosure and may have to be removed from operation and replaced with new patched versions.

• CWE-1329: Reliance on Component That is Not Updateable