CVE-2000-0844 in Unix
Summary
by MITRE
Some functions that implement the locale subsystem on Unix do not properly cleanse user-injected format strings, which allows local attackers to execute arbitrary commands via functions such as gettext and catopen.
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Analysis
by VulDB Data Team • 10/06/2024
The vulnerability described in CVE-2000-0844 represents a critical security flaw within Unix-based systems' locale subsystem implementation. This issue stems from improper handling of user-supplied format strings in functions designed to manage internationalization and localization features. The affected functions include gettext and catopen, which are fundamental components of the system's internationalization infrastructure. These functions are responsible for retrieving translated messages and opening message catalog files respectively, making them integral to how software presents information in different languages and locales.
The technical flaw manifests when these locale functions fail to properly sanitize or validate format strings provided by users or external sources. This inadequate input validation creates a classic format string vulnerability that can be exploited by local attackers who have access to the system. When maliciously crafted format strings are processed by these functions, they can manipulate the execution flow of the program and potentially execute arbitrary commands with the privileges of the affected process. The vulnerability is particularly dangerous because it operates at a low level within the system's internationalization framework, making it difficult to detect and patch without comprehensive system analysis.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it can enable attackers to gain unauthorized access to system resources and potentially compromise the entire system. Local attackers who can inject malicious format strings through the locale subsystem can leverage this weakness to execute arbitrary code, potentially leading to complete system compromise. The attack surface is significant since many system applications and services rely on proper internationalization functionality, and the vulnerability affects the core locale handling mechanisms that are fundamental to Unix system operations. This makes the exploit applicable across multiple applications and services that depend on the affected functions, amplifying the potential damage and attack vectors.
Mitigation strategies for CVE-2000-0844 should focus on comprehensive input validation and sanitization within the locale subsystem functions. System administrators should ensure that all affected applications are updated with patches that properly handle format strings and implement robust input validation mechanisms. The remediation process requires careful attention to how format strings are processed in gettext and catopen functions, with particular emphasis on preventing user-controlled data from being interpreted as format specifiers. Additionally, implementing proper access controls and limiting local user privileges can reduce the potential impact of exploitation. This vulnerability aligns with CWE-134, which specifically addresses format string vulnerabilities where format strings are constructed from user-controlled data without proper validation. The attack pattern follows typical local privilege escalation techniques documented in the MITRE ATT&CK framework under privilege escalation tactics, specifically targeting system services and core infrastructure components to achieve persistent access and control over affected systems.