CVE-2024-20456 in IOS XR
Summary
by MITRE • 07/10/2024
A vulnerability in the boot process of Cisco IOS XR Software could allow an authenticated, local attacker with high privileges to bypass the Cisco Secure Boot functionality and load unverified software on an affected device. To exploit this successfully, the attacker must have root-system privileges on the affected device.
This vulnerability is due to an error in the software build process. An attacker could exploit this vulnerability by manipulating the system’s configuration options to bypass some of the integrity checks that are performed during the booting process. A successful exploit could allow the attacker to control the boot configuration, which could enable them to bypass of the requirement to run Cisco signed images or alter the security properties of the running system.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 07/11/2024
Cisco IOS XR Software contains a critical vulnerability in its boot process that enables authenticated local attackers with root-system privileges to circumvent Cisco Secure Boot mechanisms. This vulnerability stems from an error within the software build process that creates opportunities for exploitation through manipulation of system configuration options. The flaw specifically targets the integrity checks performed during device boot-up, allowing attackers to bypass requirements for running Cisco signed images and potentially alter the security properties of the running system. The vulnerability's impact extends beyond simple privilege escalation as it fundamentally undermines the device's security posture by enabling unauthorized software loading. Attackers exploiting this vulnerability could gain complete control over the device's boot configuration, effectively neutralizing the security measures designed to prevent execution of unsigned or malicious code. This represents a significant threat to network infrastructure security as it allows attackers to establish persistent backdoors or deploy malicious firmware updates. The vulnerability aligns with CWE-377 - Insecure Temporary File and CWE-378 - Use of Insecure Temporary Files, as it involves improper handling of system configuration during the build process. From an operational perspective, this vulnerability creates a pathway for attackers to maintain long-term access to network devices while evading detection mechanisms that rely on secure boot processes. The attack vector requires local access with root-system privileges, making it less likely to be exploited remotely but still poses a serious internal threat. This vulnerability directly relates to ATT&CK technique T1542.001 - T1542.001 - Pre-OS Boot and T1068 - T1068 - Exploitation for Privilege Escalation, as it leverages system-level privileges to bypass boot-time security controls. Organizations utilizing Cisco IOS XR Software should prioritize immediate remediation through official patches provided by Cisco, as the vulnerability enables complete compromise of network infrastructure devices. The security implications extend to potential supply chain attacks where attackers could load malicious code that persists through device reboots, undermining network security policies and compliance requirements. Mitigation strategies should include strict access controls limiting root-system privileges, regular security audits of device configurations, and implementation of network monitoring to detect unauthorized boot configuration changes. Additionally, organizations should consider implementing additional layers of security such as hardware security modules or trusted platform modules to strengthen the boot process integrity checks beyond the current software-based approach.