CVE-2020-3458 in ASA
Summary
by MITRE • 10/22/2020
Multiple vulnerabilities in the secure boot process of Cisco Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software for the Firepower 1000 Series and Firepower 2100 Series Appliances could allow an authenticated, local attacker to bypass the secure boot mechanism. The vulnerabilities are due to insufficient protections of the secure boot process. An attacker could exploit these vulnerabilities by injecting code into specific files that are then referenced during the device boot process. A successful exploit could allow the attacker to break the chain of trust and inject code into the boot process of the device, which would be executed at each boot and maintain persistence across reboots.
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Analysis
by VulDB Data Team • 08/12/2026
The vulnerability identified as CVE-2020-3458 represents a critical weakness in the secure boot mechanisms of Cisco Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software running on Firepower 1000 Series and Firepower 2100 Series appliances. This flaw resides within the fundamental trust chain that ensures only authorized code executes during system boot, creating a pathway for persistent malicious activity that can evade traditional security measures. The vulnerability stems from inadequate protection mechanisms during the boot process, specifically targeting the integrity checks that should validate the authenticity and integrity of boot components.
The technical exploitation of this vulnerability requires an authenticated local attacker who can manipulate specific files that are referenced during the device boot sequence. This attack vector operates through code injection techniques that target the boot process itself, rather than attempting to compromise the running system. The flaw allows attackers to break the chain of trust by inserting malicious code into files that are loaded during boot, effectively creating a backdoor that persists across system reboots. This represents a sophisticated attack method that leverages the legitimate boot process to establish persistence, making detection and remediation particularly challenging.
The operational impact of CVE-2020-3458 extends beyond simple unauthorized access, as it enables attackers to establish persistent footholds within network security infrastructure. Once successfully exploited, the malicious code executes at every boot cycle, maintaining long-term presence without requiring repeated exploitation attempts. This persistence capability aligns with attack patterns described in the MITRE ATT&CK framework under the T1547.001 technique for Boot or Logon Autostart Execution, where adversaries establish persistence by modifying boot processes. The vulnerability affects critical network security devices, potentially allowing attackers to compromise network traffic monitoring, access control enforcement, and threat detection capabilities.
Security professionals should implement immediate mitigations including regular firmware updates from Cisco, which address the underlying secure boot protection deficiencies. Network segmentation and monitoring of boot process activities can help detect unauthorized modifications. The vulnerability demonstrates the importance of hardware security modules and proper secure boot implementations as outlined in NIST SP 800-155 and ISO/IEC 27031 standards. Organizations should also conduct thorough security assessments of their network infrastructure to identify any potential exploitation attempts and implement continuous monitoring of boot process integrity. The attack scenario represents a significant concern for organizations relying on these appliances for network security, as it undermines the fundamental security assumptions of their defensive infrastructure.
This vulnerability type falls under CWE-377 - Insecure Temporary File Creation and CWE-378 - Creation of Temporary File With Insecure Permissions, though more specifically relates to secure boot chain integrity violations. The attack methodology aligns with techniques described in the ATT&CK framework for privilege escalation and persistence, particularly targeting system-level components that are critical for maintaining security posture. Organizations should treat this vulnerability as a high-priority remediation item due to its potential for establishing persistent backdoors within core network security infrastructure, requiring immediate attention from security operations teams to prevent exploitation and maintain network integrity.