CVE-1999-1490 in Linux
Summary
by MITRE
xosview 1.5.1 in Red Hat 5.1 allows local users to gain root access via a long HOME environmental variable.
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Analysis
by VulDB Data Team • 10/20/2024
The vulnerability described in CVE-1999-1490 represents a classic buffer overflow issue affecting xosview version 1.5.1 distributed with Red Hat Linux 5.1. This security flaw exploits a weakness in how the application handles environmental variables, specifically the HOME variable, which can be manipulated by local users to execute arbitrary code with elevated privileges. The vulnerability stems from inadequate input validation and bounds checking within the application's environmental variable processing logic, creating a pathway for privilege escalation attacks.
The technical implementation of this vulnerability involves a buffer overflow condition that occurs when the xosview application processes a specially crafted HOME environment variable exceeding its allocated memory buffer size. This type of flaw falls under CWE-121, which categorizes buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations. The vulnerability is particularly dangerous because it operates at the local user level, meaning any user with access to the system can potentially exploit this weakness to gain root privileges, making it a critical security concern for multi-user environments. The attack vector specifically targets the application's handling of environmental variables during program initialization, where the HOME variable is processed without proper length validation.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it fundamentally undermines the security model of the affected system. Local users can leverage this weakness to execute arbitrary code with root privileges, potentially leading to complete system compromise, data exfiltration, or persistent backdoor installation. The vulnerability affects systems running Red Hat Linux 5.1 with xosview 1.5.1, representing a significant risk to enterprise environments where multiple users share systems and proper privilege separation is essential. From an attacker's perspective, this vulnerability provides a straightforward path to gaining administrative control without requiring network access or complex exploitation techniques, making it particularly attractive for malicious actors. The impact is further exacerbated by the fact that this was a local privilege escalation vulnerability that could be exploited without network connectivity, aligning with ATT&CK technique T1068 which covers local privilege escalation through application vulnerabilities.
Mitigation strategies for CVE-1999-1490 should focus on both immediate patching and defensive measures. The primary solution involves updating to a patched version of xosview that properly validates environmental variable lengths and implements robust bounds checking mechanisms. System administrators should also consider implementing additional security controls such as restricting the HOME environment variable through system configuration or using security modules like SELinux to limit the impact of such vulnerabilities. The vulnerability demonstrates the importance of proper input validation in security-critical applications and highlights the need for regular security updates and vulnerability assessments. Organizations should also consider implementing monitoring for unusual environmental variable usage patterns and ensure that all applications properly validate user inputs to prevent similar buffer overflow conditions from occurring in other system components. Additionally, the incident underscores the necessity of following security best practices such as implementing the principle of least privilege and regularly auditing system configurations to minimize the attack surface available to potential exploiters.