CVE-2002-1605 in HP-UX
Summary
by MITRE
Buffer overflow in HP Tru64 UNIX 5.1a, 5.1, 5.0a, 4.0g, and 4.0f allows attackers to execute arbitrary code via a long _XKB_CHARSET environment variable to (1) dxpause, (2) dxconsole, or (3) dtsession.
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Analysis
by VulDB Data Team • 03/01/2025
The vulnerability described in CVE-2002-1605 represents a critical buffer overflow flaw affecting Hewlett-Packard Tru64 UNIX operating system versions 5.1a, 5.1, 5.0a, 4.0g, and 4.0f. This security weakness resides in the X Keyboard Extension handling mechanism within specific system utilities, creating a pathway for malicious code execution through environment variable manipulation. The flaw specifically targets three distinct executables: dxpause, dxconsole, and dtsession, which are part of the X Window System implementation on Tru64 UNIX platforms. The vulnerability manifests when these utilities process the _XKB_CHARSET environment variable, which is used to define keyboard character sets within the X11 environment.
The technical implementation of this buffer overflow occurs due to inadequate bounds checking when processing the _XKB_CHARSET environment variable. When an attacker supplies an excessively long string value for this environment variable, the system fails to properly validate the input length before copying it into a fixed-size buffer. This classic buffer overflow condition allows the attacker to overwrite adjacent memory locations, potentially corrupting program execution flow and enabling arbitrary code execution with the privileges of the affected process. The vulnerability is particularly dangerous because it affects system-level utilities that typically run with elevated privileges, providing attackers with potential escalation opportunities. The flaw aligns with CWE-121, which describes heap-based buffer overflow conditions, and represents a direct violation of secure coding practices that mandate proper input validation and boundary checking.
The operational impact of this vulnerability extends beyond simple code execution, as it compromises the integrity and confidentiality of systems running affected Tru64 UNIX versions. Attackers exploiting this weakness could gain unauthorized access to system resources, potentially leading to complete system compromise and persistent backdoor access. The affected utilities dxpause, dxconsole, and dtsession are commonly used in graphical environments, making this vulnerability exploitable in both local and remote attack scenarios. The vulnerability's presence in multiple versions of Tru64 UNIX indicates a widespread exposure across the platform, affecting organizations that relied on these older operating system releases for critical infrastructure. From an adversary perspective, this vulnerability maps to ATT&CK technique T1059.007 for command and scripting interpreter, as successful exploitation would enable execution of arbitrary commands through the compromised utilities.
Mitigation strategies for CVE-2002-1605 should prioritize immediate system updates and patches provided by Hewlett-Packard to address the buffer overflow conditions in the affected software components. Organizations should implement environment variable sanitization measures to prevent malicious input from reaching vulnerable applications, particularly focusing on restricting the length and content of _XKB_CHARSET values. System administrators should conduct comprehensive vulnerability assessments to identify all instances of the affected executables and ensure proper access controls are implemented to limit potential exploitation vectors. Network segmentation and privilege separation practices should be reinforced to minimize the impact if exploitation occurs. Additionally, monitoring systems should be configured to detect unusual environment variable usage patterns that might indicate attempted exploitation of this vulnerability. The remediation approach should also include updating to supported Tru64 UNIX versions that contain the necessary security patches and implementing security awareness training for system administrators to recognize and respond to similar buffer overflow threats in other system components.