CVE-2017-7564 in Trusted Firmware
Summary
by MITRE
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.
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Analysis
by VulDB Data Team • 06/08/2026
The vulnerability identified as CVE-2017-7564 affects ARM Trusted Firmware versions through 1.3 and represents a critical security flaw in the implementation of the secure self-hosted invasive debug interface. This vulnerability exists within the ARM architecture's trust zone implementation where the secure world operates in isolation from the normal world to protect sensitive operations and data. The issue arises from insufficient validation of debug exceptions and debug register operations that originate from the normal world, creating a pathway for malicious actors to exploit the system's debug interface mechanisms. The ARM Trusted Firmware serves as a critical component in implementing the trust zone architecture, providing the foundational secure runtime environment that protects against unauthorized access to cryptographic keys, secure boot processes, and other sensitive operations.
The technical flaw manifests when normal world processes attempt to manipulate debug registers or trigger debug exceptions in ways that bypass the normal security boundaries between the normal and secure worlds. Specifically, the vulnerability occurs during the handling of debug events where the secure world fails to properly validate or sanitize inputs from the normal world debug interface. This allows attackers to craft malicious debug register configurations or exception sequences that can cause the secure world to panic and terminate operations. The debug interface in ARM systems is designed to provide legitimate debugging capabilities for developers and system administrators, but when improperly controlled, it becomes a potential attack vector that can be exploited to disrupt secure operations. The vulnerability is particularly concerning because it operates at a low level within the system architecture, making it difficult to detect and prevent through traditional software-based security measures.
The operational impact of this vulnerability extends beyond simple denial of service scenarios to potentially compromise the integrity of the entire secure execution environment. When the secure world panics due to malicious debug interface manipulation, it can result in complete system shutdown or forced reboot, effectively denying legitimate users access to secure services. More critically, this vulnerability could potentially be leveraged as a stepping stone for more sophisticated attacks that might attempt to escalate privileges or extract sensitive information from the secure world. The attack surface is particularly wide because debug interfaces are often enabled during system development and testing phases, and may remain active in production systems for maintenance purposes. Organizations implementing ARM-based secure systems face significant risk if this vulnerability is not addressed, as it undermines the fundamental security assumptions of the trust zone architecture.
Mitigation strategies for CVE-2017-7564 should focus on implementing proper input validation and access control mechanisms within the debug interface handlers in the ARM Trusted Firmware. System administrators should ensure that debug interfaces are disabled or properly restricted in production environments where they are not required for legitimate operational purposes. The implementation of proper firmware updates to versions that address this vulnerability is essential, as ARM has released patched versions of their Trusted Firmware that properly validate debug register operations and prevent malicious manipulation of debug exceptions. Security monitoring should include detection of unusual debug interface activity patterns that might indicate exploitation attempts. This vulnerability aligns with CWE-248, which addresses "Uncaught Exception" in software systems, and relates to ATT&CK technique T1059.001 for command and scripting interpreter, as attackers may attempt to leverage debug interfaces for system manipulation. Organizations should also consider implementing runtime protection mechanisms and regular security assessments to detect potential exploitation attempts that might target similar low-level system interfaces.