The ARM TrustZone Technology on which Trusty is based on contains a vulnerability in access permission settings where the portion of the DRAM reserved for TrustZone is identity-mapped by TLK with read, write, and execute permissions, which gives write access to kernel code and data that is otherwise mapped read only.

References

• https://nvd.nist.gov/vuln/detail/CVE-2021-34387
• https://nvidia.custhelp.com/app/answers/detail/a_id/5205