CVE-1999-0942 in UnixWare
Summary
by MITRE
UnixWare dos7utils allows a local user to gain root privileges by using the STATICMERGE environmental variable to find a script which it executes.
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Analysis
by VulDB Data Team • 04/19/2026
The vulnerability identified as CVE-1999-0942 represents a classic local privilege escalation flaw within the UnixWare operating system's dos7utils package. This issue stems from improper handling of environment variables during script execution processes, specifically involving the STATICMERGE variable that controls how certain system utilities merge files. The flaw enables a local attacker to manipulate the execution environment in a manner that ultimately results in arbitrary code execution with root privileges.
The technical mechanism behind this vulnerability operates through environment variable manipulation within the dos7utils framework. When the STATICMERGE variable is set by an attacker, it influences how the system locates and executes supporting scripts during the utility's operation. This particular implementation fails to properly validate or sanitize the environment variable contents, allowing an attacker to inject malicious paths or commands that get executed with elevated privileges. The vulnerability is classified under CWE-78 as a "Improper Neutralization of Special Elements used in an OS Command" and aligns with ATT&CK technique T1068 for privilege escalation through environment variable manipulation.
The operational impact of this vulnerability is significant as it provides a straightforward path for local users to achieve root access without requiring authentication or complex exploitation techniques. Attackers can leverage this flaw by simply setting the STATICMERGE variable to point to a malicious script in a location they control, then executing the dos7utils utility. The vulnerability affects systems running UnixWare where the dos7utils package is installed and accessible to local users, creating a persistent security risk that could be exploited by both malicious insiders and external attackers who have gained initial access to the system.
Mitigation strategies for this vulnerability should focus on immediate system hardening and access control measures. System administrators should ensure that the dos7utils package is properly secured through restrictive file permissions and that environment variables are not exposed to untrusted users. The recommended approach includes implementing proper input validation and sanitization for environment variables, restricting write access to system utility directories, and monitoring for unauthorized modifications to critical system scripts. Additionally, organizations should consider applying vendor patches or upgrading to newer versions of UnixWare that address this specific privilege escalation vector. The vulnerability highlights the importance of secure coding practices and proper environment variable handling in system utilities, as outlined in security standards such as the OWASP Top Ten and NIST cybersecurity guidelines for privilege escalation prevention.