CVE-2020-26541 Explained : Impact and Mitigation

The Linux kernel through 5.8.13 has a vulnerability related to Secure Boot Forbidden Signature Database enforcement.

Understanding CVE-2020-26541

This CVE involves a weakness in enforcing the Secure Boot Forbidden Signature Database protection mechanism in the Linux kernel.

What is CVE-2020-26541?

The Linux kernel through version 5.8.13 fails to adequately enforce the Secure Boot Forbidden Signature Database protection, impacting specific files.

The Impact of CVE-2020-26541

The vulnerability has a CVSS base score of 6.5, with high impacts on confidentiality, integrity, and availability, requiring high privileges and user interaction.

Technical Details of CVE-2020-26541

This section delves into the technical aspects of the CVE.

Vulnerability Description

The issue affects certs/blacklist.c and certs/system_keyring.c within the Linux kernel, leading to inadequate enforcement of Secure Boot Forbidden Signature Database protection.

Affected Systems and Versions

Affected Version: Linux kernel through 5.8.13
Specific Files: certs/blacklist.c and certs/system_keyring.c

Exploitation Mechanism

Attack Complexity: Low
Attack Vector: Local
Privileges Required: High
User Interaction: Required
Scope: Unchanged

Mitigation and Prevention

Protecting systems from CVE-2020-26541 is crucial. Here are some steps to mitigate and prevent exploitation.

Immediate Steps to Take

Monitor vendor updates for patches
Implement secure boot mechanisms
Restrict access to critical system files

Long-Term Security Practices

Regularly update the Linux kernel
Conduct security assessments and audits
Educate users on secure boot best practices

Patching and Updates

Apply patches provided by the Linux kernel maintainers
Stay informed about security advisories and updates