In ARM Trusted Firmware 1.3, RO memory is always executable at AArch64 Secure EL1, allowing attackers to bypass the MTEXECUTENEVER protection mechanism. This issue occurs because of inconsistency in the number of execute-never bits (one bit versus two bits).

In ARM Trusted Firmware through 1.3, the secure self-hosted invasive debug interface allows normal world attackers to cause a denial of service (secure world panic) via vectors involving debug exceptions and debug registers.

The BL1 FWU SMC handling code in ARM Trusted Firmware before 1.4 might allow attackers to write arbitrary data to secure memory, bypass the bl1platmemcheck protection mechanism, cause a denial of service, or possibly have unspecified other impact via a crafted AArch32 image, which triggers an integer overflow.