CVE-2013-1060 in Linux
Summary
by MITRE
A certain Ubuntu build procedure for perf, as distributed in the Linux kernel packages in Ubuntu 10.04 LTS, 12.04 LTS, 12.10, 13.04, and 13.10, sets the HOME environment variable to the ~buildd directory and consequently reads the system configuration file from the ~buildd directory, which allows local users to gain privileges by leveraging control over the buildd account.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 05/24/2021
The vulnerability identified as CVE-2013-1060 represents a privilege escalation flaw within the Ubuntu build infrastructure for the perf tool, which is part of the Linux kernel packages. This issue specifically affects Ubuntu LTS versions 10.04, 12.04, and non-LTS versions 12.10, 13.04, and 13.10. The vulnerability stems from an insecure build procedure that improperly handles environment variable configuration during the compilation process. When the perf tool is built within the Ubuntu packaging system, the build process sets the HOME environment variable to point to the ~buildd directory, which is a dedicated build account directory used for package compilation activities. This seemingly innocuous configuration creates a significant security risk because it causes the system to read configuration files from the buildd account's home directory instead of the standard system locations. The flaw manifests when local users who have access to the buildd account or can influence its environment can manipulate configuration files in the ~buildd directory, thereby gaining elevated privileges. This vulnerability aligns with CWE-276, which describes improper privilege management, and specifically relates to CWE-73, which addresses external control of file name or path. The attack vector operates through the principle of privilege escalation by leveraging the build environment's misconfiguration.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it allows attackers to potentially compromise the entire build infrastructure and subsequently the systems that rely on these packages. When an attacker controls the buildd account environment, they can inject malicious configuration settings that persist across builds, potentially affecting multiple packages and installations. The vulnerability demonstrates how build-time security flaws can have long-lasting consequences in system security, as the compromised build environment can be used to create malicious packages that are then distributed to users. This particular issue is classified under the ATT&CK framework as privilege escalation through environment variable manipulation, specifically targeting build and development environments. The vulnerability is particularly concerning because it operates at the system level where package builds occur, potentially allowing attackers to modify system configuration files that are read during normal system operation. The flaw essentially provides a backdoor mechanism through which unprivileged users can influence the build process and gain elevated privileges, making it a critical security concern for any system that relies on Ubuntu package building infrastructure.
Mitigation strategies for CVE-2013-1060 must address both the immediate build environment configuration and the broader security posture of package building systems. The primary fix involves modifying the build procedures to ensure that environment variables such as HOME are not set to potentially compromised directories during package compilation, particularly when dealing with dedicated build accounts. System administrators should implement strict access controls for the buildd account and monitor for unauthorized modifications to build environment files. Additionally, the build infrastructure should be configured to use secure temporary directories that are not accessible to unprivileged users. Organizations should also consider implementing automated checks that verify the integrity of build environments and configuration files. The vulnerability highlights the importance of secure coding practices in build systems and the need for regular security audits of package building infrastructure. Network segmentation and privilege separation should be implemented to prevent lateral movement if an attacker compromises the buildd account. Regular updates and patches should be applied to ensure that all affected Ubuntu versions are protected, and security monitoring should be enhanced to detect anomalous build activity that might indicate exploitation attempts. This vulnerability serves as a reminder that security must be considered throughout the entire software development lifecycle, including the build and packaging phases where such subtle but critical flaws can exist.