CVE-2016-1611 in Filr
Summary
by MITRE
Novell Filr 1.2 before Hot Patch 6 and 2.0 before Hot Patch 2 uses world-writable permissions for /etc/profile.d/vainit.sh, which allows local users to gain privileges by replacing this file's content with arbitrary shell commands.
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Analysis
by VulDB Data Team • 08/19/2024
The vulnerability identified as CVE-2016-1611 affects Novell Filr versions 1.2 prior to Hot Patch 6 and 2.0 prior to Hot Patch 2, representing a critical privilege escalation flaw that exploits weak file permissions within the system's profile initialization mechanism. This issue resides in the /etc/profile.d/vainit.sh file which is configured with world-writable permissions, creating an exploitable entry point for local attackers to elevate their system privileges. The flaw demonstrates a classic security misconfiguration where system-critical initialization files are improperly secured, allowing unauthorized users to modify essential system components that execute during user login processes.
The technical implementation of this vulnerability stems from the improper permission settings on the vainit.sh file located in the system's profile.d directory. This directory contains scripts that are executed automatically during shell initialization for all users, making it a prime target for privilege escalation attacks. When a local user can write to this file, they can inject malicious shell commands that will execute with elevated privileges during subsequent user sessions. The vulnerability directly maps to CWE-732: Incorrect Permission Assignment for Critical Resource, which specifically addresses situations where critical system resources are assigned insufficient permissions, allowing unauthorized modification. The flaw represents a failure in the principle of least privilege, where system files that should be restricted to administrative access are instead accessible for modification by any local user.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with a persistent backdoor mechanism within the target system. Once an attacker replaces the vainit.sh content with malicious commands, these modifications will execute automatically whenever users log into the system, enabling ongoing unauthorized access and potential data exfiltration. The attack vector is particularly concerning because it requires minimal privileges to exploit and can remain undetected for extended periods. According to ATT&CK framework, this vulnerability aligns with T1068: Exploitation for Privilege Escalation and T1546.004: Event Triggered Execution, as it leverages system initialization processes to maintain persistence and execute malicious code with elevated privileges. The vulnerability affects both the 1.2 and 2.0 product lines, indicating it was a widespread issue that impacted multiple versions of the Filr platform.
Mitigation strategies for CVE-2016-1611 require immediate implementation of proper file permission controls on the affected system files. The primary remediation involves changing the permissions of /etc/profile.d/vainit.sh to restrict write access to only the root user or designated administrative accounts, typically achieved through chmod 644 or similar restrictive settings. Organizations should also implement regular security audits to identify and correct similar permission misconfigurations across their systems. The most effective long-term solution involves applying the vendor-provided hot patches for Novell Filr versions 1.2 through Hot Patch 6 and 2.0 through Hot Patch 2, which address the underlying permission issues. Additionally, system administrators should conduct comprehensive permission reviews of all files within /etc/profile.d/ and similar system directories to ensure that critical initialization scripts maintain appropriate access controls. The vulnerability serves as a reminder of the importance of maintaining proper file permissions and the potential consequences of failing to address even seemingly minor security misconfigurations in system initialization processes.