The bootloader in the Nokia ASIK AirScale system module (versions 474021A.101 and 474021A.102) loads public keys for firmware verification signature. If an attacker modifies the flash contents to corrupt the keys, secure boot could be permanently disabled on a given device.
Immutable data, such as a first-stage bootloader, device identifiers, and “write-once” configuration settings are stored in writable memory that can be re-programmed or updated in the field.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Asik_airscale_474021a.102_firmware | Nokia | - (including) | - (including) |
Security services such as secure boot, authentication of code and data, and device attestation all require assets such as the first stage bootloader, public keys, golden hash digests, etc. which are implicitly trusted. Storing these assets in read-only memory (ROM), fuses, or one-time programmable (OTP) memory provides strong integrity guarantees and provides a root of trust for securing the rest of the system. Security is lost if assets assumed to be immutable can be modified.