CVE-2000-0997 in NetBSD
Summary
by MITRE
Format string vulnerabilities in eeprom program in OpenBSD, NetBSD, and possibly other operating systems allows local attackers to gain root privileges.
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Analysis
by VulDB Data Team • 04/06/2019
The vulnerability described in CVE-2000-0997 represents a critical format string flaw within the eeprom program distributed with OpenBSD and NetBSD operating systems. This vulnerability specifically affects the eeprom utility which is responsible for reading and writing data to the system's eeprom device, commonly used for storing hardware configuration information and system identification data. The flaw arises from improper handling of user-supplied input within the program's printf-family function calls, creating a condition where maliciously crafted input can be interpreted as format specifiers rather than literal data.
The technical implementation of this vulnerability stems from the eeprom program's failure to properly sanitize input parameters before passing them to format string functions such as printf, fprintf, or sprintf. When the program processes user-provided arguments without adequate validation or escaping, an attacker can inject format specifiers like %x, %s, or %n that cause the program to read from or write to arbitrary memory locations. This fundamental flaw in input validation directly maps to CWE-134, which specifically addresses the use of user-supplied format strings in functions like printf, creating a path for arbitrary code execution and memory corruption.
The operational impact of this vulnerability extends far beyond simple privilege escalation, as it provides local attackers with a direct pathway to achieve root privileges on affected systems. Since the eeprom program typically runs with elevated privileges due to its role in system hardware configuration management, successful exploitation allows attackers to gain complete control over the target system. This privilege escalation capability makes the vulnerability particularly dangerous in multi-user environments where local access might be obtained through legitimate means such as user accounts, network services, or shared system resources.
The exploitation of this vulnerability follows established patterns documented in various attack frameworks including the ATT&CK framework's privilege escalation techniques, specifically targeting the use of vulnerable system utilities to gain elevated access. Attackers typically craft malicious input that includes format specifiers designed to either read sensitive memory locations containing system information or write data to critical memory addresses to manipulate program execution flow. The vulnerability's presence in multiple operating systems including OpenBSD and NetBSD indicates a widespread issue affecting systems that rely on these specific utilities for hardware configuration management.
Mitigation strategies for CVE-2000-0997 require immediate patching of the affected eeprom utilities, as the vulnerability cannot be effectively addressed through runtime configuration changes alone. System administrators should prioritize updating their operating systems to versions containing fixed implementations of the eeprom program that properly validate all input parameters before processing. Additionally, implementing proper input sanitization measures such as using snprintf instead of sprintf, and avoiding direct use of user-supplied data in format string arguments, provides defense-in-depth protection against similar vulnerabilities. Network segmentation and privilege separation measures can help limit the potential impact if exploitation occurs, while regular security audits should verify that no other system utilities contain similar format string vulnerabilities that could be exploited in similar manners.