CVE-2000-0003 in UnixWare
Summary
by MITRE
Buffer overflow in UnixWare rtpm program allows local users to gain privileges via a long environmental variable.
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Analysis
by VulDB Data Team • 04/20/2026
The vulnerability described in CVE-2000-0003 represents a classic buffer overflow flaw within the UnixWare rtpm program that enables local privilege escalation through manipulation of environmental variables. This issue specifically affects the rtpm (Real-Time Process Manager) component of the UnixWare operating system, which is responsible for managing real-time processes and system resources. The vulnerability stems from inadequate input validation and bounds checking within the program's handling of environment variables, creating an exploitable condition that can be leveraged by local attackers to execute arbitrary code with elevated privileges.
The technical implementation of this buffer overflow occurs when the rtpm program processes environmental variables passed to it during execution. The flaw manifests as a stack-based buffer overflow where the program fails to properly validate the length of environmental variable values before copying them into fixed-size buffers. When a local user provides an environmental variable with a length exceeding the allocated buffer space, the excess data overflows into adjacent memory locations, potentially corrupting the stack and allowing for the execution of malicious code. This type of vulnerability falls under CWE-121, which specifically addresses stack-based buffer overflow conditions, and aligns with the broader category of CWE-787, which covers out-of-bounds write conditions.
The operational impact of this vulnerability is significant for UnixWare systems, as it allows any local user to potentially escalate their privileges from standard user level to root or administrative privileges. This privilege escalation capability transforms a local access point into a potential system compromise vector, enabling attackers to gain unauthorized access to sensitive system resources, modify critical files, and potentially establish persistent access. The vulnerability is particularly dangerous because it requires no network connectivity or remote access, making it exploitable through local system compromise or social engineering techniques. From an adversarial perspective, this flaw aligns with ATT&CK technique T1068, which covers local privilege escalation through exploitation of system vulnerabilities.
Mitigation strategies for this vulnerability should focus on immediate patching and system hardening measures. The most effective remediation involves applying the vendor-provided security patches that address the buffer overflow condition through proper input validation and bounds checking mechanisms. System administrators should also implement environmental variable restrictions and monitoring to detect unusual or potentially malicious variable values. Additional protective measures include enabling address space layout randomization (ASLR) where available, implementing stack canaries to detect buffer overflow attempts, and conducting regular security audits of system binaries. The vulnerability highlights the importance of secure coding practices and input validation, particularly in system-critical components that handle user-provided data. Organizations should also consider implementing privilege separation mechanisms and least privilege principles to limit the potential damage from such exploitation attempts. Regular security assessments and vulnerability scanning should be conducted to identify similar buffer overflow conditions in other system components, as this class of vulnerability remains prevalent in legacy and poorly maintained systems.