CVE-2018-18653 : Security Advisory and Response
Learn about CVE-2018-18653 affecting Ubuntu 18.10 with UEFI Secure Boot. Discover the impact, technical details, and mitigation steps for this Linux kernel vulnerability.
Ubuntu 18.10, when booted with UEFI Secure Boot enabled, is vulnerable to exploitation by privileged local users, allowing them to bypass Secure Boot restrictions and execute untrusted code.
Understanding CVE-2018-18653
What is CVE-2018-18653?
The vulnerability in the Linux kernel used in Ubuntu 18.10 enables local users to load arbitrary kernel modules, evading Secure Boot restrictions.
The Impact of CVE-2018-18653
The mishandling of signature verification results due to a modified kernel/module.c and specific configuration options can lead to the execution of untrusted code.
Technical Details of CVE-2018-18653
Vulnerability Description
The Linux kernel in Ubuntu 18.10, when UEFI Secure Boot is active, allows privileged local users to bypass Secure Boot restrictions by loading arbitrary kernel modules.
Affected Systems and Versions
- Affected System: Ubuntu 18.10
- Secure Boot Enabled
Exploitation Mechanism
- Local users exploit mishandling of signature verification results
- Modified kernel/module.c and specific configuration options contribute to the vulnerability
Mitigation and Prevention
Immediate Steps to Take
- Disable UEFI Secure Boot if not required
- Regularly monitor for security advisories and updates
Long-Term Security Practices
- Implement least privilege access controls
- Conduct regular security training for users
Patching and Updates
- Apply patches and updates provided by Ubuntu to address the vulnerability