CVE-2011-1934 in lilo
Summary
by MITRE
lilo-uuid-diskid causes lilo.conf to be world-readable in lilo 23.1.
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Analysis
by VulDB Data Team • 11/27/2019
The vulnerability described in CVE-2011-1934 relates to the Linux Loader LILO (LInux LOader) version 23.1 where the lilo-uuid-diskid utility creates a lilo.conf file with world-readable permissions. This issue arises from the improper handling of file permissions during the LILO configuration process, specifically when the utility generates disk identification information for boot loader configuration. The root cause stems from the utility not properly setting restrictive file permissions on the generated configuration file, leaving it accessible to all users on the system. This represents a privilege escalation and information disclosure vulnerability that undermines the security posture of systems relying on LILO for boot management.
The technical flaw manifests when the lilo-uuid-diskid utility executes and creates the lilo.conf file without explicitly setting appropriate permissions. The configuration file typically contains sensitive information such as disk identifiers, partition mappings, and boot parameters that could be exploited by malicious actors. This vulnerability falls under the CWE-732 category of Incorrect Permission Assignment for Critical Resource, where critical system files are created with overly permissive access controls. The flaw is particularly concerning because it affects the boot process configuration, which is a fundamental system component that requires proper security controls to prevent unauthorized modifications or information disclosure.
The operational impact of this vulnerability extends beyond simple information disclosure, as it creates potential attack vectors for system compromise. An attacker with access to a system could read the lilo.conf file to obtain detailed information about disk layouts, partition structures, and boot parameters that could be used in subsequent attacks. This information could aid in crafting more sophisticated attacks against the boot process or identifying potential targets for privilege escalation. The vulnerability also violates the principle of least privilege, as the configuration file should only be accessible to system administrators and the boot loader process itself. According to ATT&CK framework, this issue relates to T1547.001 (Boot or Logon Autostart Execution) and T1068 (Local Privilege Escalation) where improper permissions on boot configuration files can enable attackers to modify system boot processes.
Mitigation strategies for CVE-2011-1934 involve immediate remediation through proper file permission management during the LILO configuration process. System administrators should ensure that the lilo-uuid-diskid utility properly sets restrictive permissions on generated configuration files, typically limiting access to root-only read permissions. The recommended approach includes implementing proper umask settings during file creation, explicitly setting file ownership to root, and ensuring that the lilo.conf file is created with permissions such as 600 or 640 rather than the default world-readable permissions. Additionally, upgrading to a patched version of LILO that addresses this specific permission handling issue is essential. Organizations should also implement regular security audits to identify and correct similar permission issues in other system configuration files and consider implementing automated monitoring for unexpected changes to critical boot configuration files. The fix should align with security best practices outlined in NIST SP 800-53 and ISO 27001 controls for system configuration management and access control.