CVE-2016-7488 in Virtual Machine Community Edition
Summary
by MITRE
Teradata Virtual Machine Community Edition v15.10 has insecure file permissions on /etc/luminex/pkgmgr. These could allow a local user to modify its contents and execute commands as root.
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Analysis
by VulDB Data Team • 05/30/2019
The vulnerability identified as CVE-2016-7488 affects Teradata Virtual Machine Community Edition version 15.10 and represents a critical privilege escalation flaw stemming from insecure file permissions. This issue resides within the /etc/luminex/pkgmgr directory structure which contains critical system configuration files that govern package management operations. The insecure permissions allow local users to modify these files, creating a pathway for arbitrary code execution with root privileges. The flaw exploits the fundamental principle of least privilege by failing to properly restrict file access controls, enabling unauthorized modification of system-critical components. This vulnerability directly violates security best practices outlined in the Open Web Application Security Project (OWASP) Top Ten and aligns with CWE-732: Incorrect Permission Assignment for Critical Resource, which specifically addresses inadequate access control mechanisms.
The technical exploitation of this vulnerability occurs through the manipulation of package management files within the luminex directory structure. When local users can modify these configuration files, they can inject malicious code or alter execution paths that ultimately result in privilege escalation. The system's failure to properly implement file access controls means that standard user accounts can gain root-level access through these modified files. This type of vulnerability typically falls under the ATT&CK technique T1068: Exploitation for Privilege Escalation, where adversaries leverage weaknesses in system configurations to gain elevated privileges. The attack vector is particularly concerning because it requires no network connectivity and can be exploited locally, making it difficult to detect through traditional network monitoring approaches.
The operational impact of CVE-2016-7488 extends beyond simple privilege escalation to potentially compromise entire system integrity and availability. An attacker with local access can not only execute commands as root but can also modify system binaries, create backdoors, or exfiltrate sensitive data from the Teradata environment. This vulnerability effectively undermines the security model of the virtual machine by allowing local users to bypass the operating system's privilege separation mechanisms. Organizations using Teradata Virtual Machine Community Edition are particularly vulnerable because this is a community edition product that may not receive timely security updates, and the default configuration often includes overly permissive file permissions. The vulnerability creates a persistent threat vector that can be exploited for extended periods without detection, potentially leading to complete system compromise and data breaches.
Mitigation strategies for CVE-2016-7488 should focus on immediate permission correction and long-term security hardening. System administrators must immediately verify and correct file permissions on /etc/luminex/pkgmgr and related directories, ensuring that only authorized users and processes have write access. The recommended approach involves implementing proper access control lists with restrictive permissions, typically setting ownership to root and removing write permissions for non-privileged users. Organizations should also implement regular security auditing procedures to identify similar permission misconfigurations across their systems. Additionally, the use of automated patch management systems and security configuration baselines can prevent such issues from recurring. The vulnerability highlights the importance of adhering to security standards such as the Center for Internet Security (CIS) Benchmarks and NIST Special Publication 800-53, which emphasize proper file permission management as a fundamental security control. Regular security assessments and penetration testing should include verification of file access controls to prevent exploitation of similar privilege escalation vulnerabilities.