CVE-2020-10713 in grub2
Summary
by MITRE
A flaw was found in grub2, prior to version 2.06. An attacker may use the GRUB 2 flaw to hijack and tamper the GRUB verification process. This flaw also allows the bypass of Secure Boot protections. In order to load an untrusted or modified kernel, an attacker would first need to establish access to the system such as gaining physical access, obtain the ability to alter a pxe-boot network, or have remote access to a networked system with root access. With this access, an attacker could then craft a string to cause a buffer overflow by injecting a malicious payload that leads to arbitrary code execution within GRUB. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
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Analysis
by VulDB Data Team • 03/18/2026
The vulnerability identified as CVE-2020-10713 resides within the GRUB2 bootloader implementation and represents a critical security flaw that undermines fundamental system integrity mechanisms. This vulnerability affects GRUB2 versions prior to 2.06 and specifically targets the bootloader's verification process, which is designed to ensure that only trusted operating system components are loaded during system boot. The flaw creates a pathway for attackers to manipulate the boot process and potentially bypass Secure Boot protections that are essential for maintaining system security. The vulnerability is classified under CWE-121 as a stack-based buffer overflow, which occurs when a program writes data beyond the boundaries of a fixed-length buffer, leading to unpredictable behavior and potential code execution. This type of vulnerability is particularly dangerous in bootloader contexts because it can be exploited before the operating system has a chance to implement its own security measures, effectively compromising the entire system security architecture.
The technical exploitation of this vulnerability requires an attacker to first gain access to the target system through physical access, PXE boot network manipulation, or remote access with root privileges. Once established, the attacker can craft a malicious payload that triggers a buffer overflow within the GRUB2 environment, allowing for arbitrary code execution directly within the bootloader context. This capability enables the attacker to load untrusted or modified kernels, effectively bypassing the Secure Boot chain of trust that is fundamental to modern system security. The exploitation process leverages the inherent trust placed in the bootloader to execute code before the operating system's security mechanisms are active, making it particularly insidious. The vulnerability's impact extends beyond simple code execution to encompass data confidentiality, integrity, and system availability, as demonstrated by the potential for complete system compromise and persistent backdoor installation. The attack vector aligns with ATT&CK technique T1068 which describes the use of local privilege escalation to gain system-level access, and T1542.001 which covers the exploitation of boot and logon processes for persistence.
The operational impact of CVE-2020-10713 is severe and far-reaching, as it fundamentally compromises the security posture of affected systems by undermining the core boot process security mechanisms. Systems running vulnerable versions of GRUB2 are susceptible to complete compromise, as attackers can load malicious kernels that can persist across reboots and evade traditional endpoint protection measures. The vulnerability's ability to bypass Secure Boot protections means that even systems configured with hardware-level security features become vulnerable to attack, as the bootloader itself becomes a point of compromise. Organizations with systems that have physical access controls or network-based boot capabilities face particularly high risk, as these access points provide the necessary entry points for exploitation. The vulnerability's persistence across system reboots makes it especially dangerous for enterprise environments where maintaining system integrity is critical, and the potential for widespread compromise increases when multiple systems share similar vulnerable bootloader configurations. This vulnerability represents a significant threat to both government and enterprise security infrastructure, as it can be exploited to establish persistent access to critical systems without detection.
Mitigation strategies for CVE-2020-10713 focus primarily on upgrading to GRUB2 version 2.06 or later, which contains patches addressing the buffer overflow vulnerability. System administrators should prioritize updating all affected systems and verifying that the update was successful through proper validation procedures. Additional mitigations include implementing physical security controls to prevent unauthorized access to systems, particularly those with network boot capabilities, and monitoring network traffic for signs of PXE boot exploitation attempts. Organizations should also consider implementing additional boot integrity monitoring solutions that can detect unauthorized modifications to bootloader configurations. The vulnerability's classification as a buffer overflow makes it susceptible to various exploitation techniques, so implementing robust input validation and memory protection mechanisms becomes crucial. Security teams should conduct thorough vulnerability assessments to identify all systems running vulnerable GRUB2 versions and prioritize remediation efforts based on risk assessment. Network segmentation and access control measures can help reduce the attack surface by limiting potential access points for exploitation, while regular security audits can help detect and prevent unauthorized modifications to boot configurations. The mitigation approach aligns with security best practices outlined in NIST SP 800-171 and ISO 27001 standards for protecting system integrity and preventing unauthorized system modifications.