CVE-2001-0426 in Solaris
Summary
by MITRE
Buffer overflow in dtsession on Solaris, and possibly other operating systems, allows local users to gain privileges via a long LANG environmental variable.
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Analysis
by VulDB Data Team • 01/14/2025
The vulnerability identified as CVE-2001-0426 represents a critical buffer overflow flaw in the dtsession component of Solaris operating systems, with potential implications extending to other Unix-like platforms. This vulnerability resides within the Desktop Services session management utility that handles user authentication and desktop environment initialization. The flaw manifests when the system processes the LANG environment variable, which specifies the locale and language settings for user sessions. When an attacker provides an excessively long LANG variable value, the dtsession utility fails to properly validate input length, leading to memory corruption that can be exploited to execute arbitrary code with elevated privileges. The vulnerability specifically affects the handling of locale information during desktop session initialization, where the application uses a fixed-size buffer that cannot accommodate oversized input data.
This buffer overflow vulnerability directly maps to CWE-121, which describes heap-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory locations. The flaw exploits the fundamental weakness in input validation mechanisms within the dtsession utility, which fails to implement proper string length verification before copying the LANG variable into internal buffers. The operational impact of this vulnerability extends beyond simple privilege escalation as it provides attackers with a reliable method to gain elevated system access through local user accounts. The attack vector requires only local system access since the vulnerability exists within a component that runs with sufficient privileges to manipulate system resources and potentially escalate to root access levels. The exploitation process typically involves crafting a specially formatted LANG environment variable that exceeds the buffer capacity, causing a stack overflow that can be manipulated to redirect program execution flow.
The security implications of CVE-2001-0426 align with ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation' by leveraging local system vulnerabilities. The vulnerability's presence in Solaris desktop environments makes it particularly concerning for enterprise deployments where multiple users may have local access to systems. Attackers can leverage this flaw to establish persistent access, modify system configurations, or exfiltrate sensitive data from systems where desktop services are enabled. The exploitation process often involves careful crafting of environment variables to ensure the overflow occurs at predictable memory locations, enabling successful code injection and privilege elevation. System administrators should note that the vulnerability affects not just Solaris but potentially other Unix systems that implement similar session management utilities, making it a widespread concern across multiple operating system families.
Mitigation strategies for this vulnerability include immediate patching of affected Solaris systems through official Oracle security updates, which address the buffer overflow by implementing proper input validation and bounds checking. System administrators should also implement environment variable sanitization policies that restrict the length of LANG and related locale variables passed to desktop services. The implementation of privilege separation mechanisms and mandatory access controls can help limit the impact of successful exploitation attempts. Additional protective measures include monitoring for unusual environment variable patterns in system logs, implementing regular security audits of desktop service configurations, and applying the principle of least privilege to reduce the potential damage from successful attacks. Organizations should also consider disabling unnecessary desktop services when they are not required for system operation, thereby reducing the attack surface available to potential exploiters.