CVE-2003-0830 in marbles
Summary
by MITRE
Buffer overflow in marbles 1.0.2 and earlier allows local users to gain privileges via a long HOME environment variable.
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Analysis
by VulDB Data Team • 11/19/2024
The vulnerability described in CVE-2003-0830 represents a classic buffer overflow flaw affecting the marbles game utility version 1.0.2 and earlier. This issue specifically targets the handling of environment variables, particularly the HOME variable, which is fundamental to Unix-like operating systems. The marbles game, a simple puzzle game often included in desktop environments, was found to improperly validate the length of the HOME environment variable during its initialization process. When a local user sets an excessively long HOME variable, the application fails to perform adequate bounds checking, leading to a buffer overflow condition that can be exploited to execute arbitrary code with elevated privileges.
This vulnerability operates under the Common Weakness Enumeration CWE-121, which categorizes buffer overflow conditions as critical security flaws that occur when more data is written to a buffer than it can hold. The technical implementation of this flaw demonstrates how environment variable handling can create exploitable conditions within seemingly benign applications. The buffer overflow in marbles occurs during the application's startup sequence when it attempts to process the HOME environment variable, which typically contains the user's home directory path. The application allocates a fixed-size buffer to store this path information but does not validate that the input data fits within these boundaries, creating a predictable overflow scenario.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it enables local users to potentially compromise system integrity and gain elevated access rights. Attackers can craft a specially constructed HOME environment variable that, when processed by marbles, triggers the buffer overflow and allows them to overwrite critical memory locations including return addresses or function pointers. This creates a pathway for executing malicious code with the privileges of the target user, which in many cases may be the root user if the application is setuid or runs with elevated permissions. The vulnerability is particularly concerning because it requires no network access and can be exploited through local environment manipulation, making it a significant concern for system administrators and security professionals.
Mitigation strategies for this vulnerability should focus on both immediate patching and broader system hardening approaches. The most effective solution involves upgrading to a patched version of marbles that properly validates environment variable lengths and implements robust input sanitization. System administrators should also consider implementing environment variable restrictions through configuration management tools and monitoring systems to detect unusual HOME variable lengths. Additionally, the principle of least privilege should be enforced by ensuring that applications do not run with unnecessary elevated permissions, and that setuid binaries are carefully audited for similar vulnerabilities. The ATT&CK framework categorizes this type of vulnerability under privilege escalation techniques, specifically noting that local users can leverage environment variable manipulation to gain elevated access rights. Organizations should implement comprehensive vulnerability management processes that include regular scanning for such buffer overflow conditions in legacy applications and maintain up-to-date security patches for all system components, particularly those with elevated privileges or setuid capabilities.