CVE-2000-0467 in splitvt
Summary
by MITRE
Buffer overflow in Linux splitvt 1.6.3 and earlier allows local users to gain root privileges via a long password in the screen locking function.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 12/06/2024
The vulnerability described in CVE-2000-0467 represents a critical buffer overflow flaw within the Linux splitvt utility version 1.6.3 and earlier. This issue specifically affects the screen locking functionality of the splitvt program, which is designed to manage virtual terminals in Linux systems. The vulnerability arises from inadequate input validation within the password handling mechanism, creating an exploitable condition that can be leveraged by local attackers to escalate privileges to root level access. The splitvt utility was commonly used in terminal management and virtual console environments, making this vulnerability particularly concerning for system administrators and security professionals.
The technical implementation of this buffer overflow occurs when the screen locking function processes user input for password validation. The flaw stems from a classic buffer overrun condition where the program fails to properly check the length of user-provided passwords before copying them into fixed-size buffers. This inadequate boundary checking allows attackers to overflow the allocated buffer space and overwrite adjacent memory locations, potentially including return addresses and control data structures. The vulnerability specifically targets the password input field within the screen locking mechanism, where a sufficiently long password input can cause the overflow to occur during the authentication process. This type of vulnerability is classified under CWE-121 as a stack-based buffer overflow, representing a fundamental memory safety issue that has been a persistent concern in system security.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with complete system control through local access. Local users who can execute programs on the target system can exploit this flaw without requiring network connectivity or external attack vectors, making it particularly dangerous in multi-user environments where users might have legitimate access to system resources. The exploitation process typically involves crafting a malicious password input that exceeds the buffer boundaries, potentially allowing attackers to overwrite critical memory segments and redirect program execution flow. This vulnerability directly violates the principle of least privilege and can lead to complete system compromise, data theft, and persistent access. The attack vector is classified under ATT&CK technique T1068 as a local privilege escalation, with the potential to establish persistent backdoors and maintain unauthorized access to affected systems.
Mitigation strategies for this vulnerability require immediate system updates and patch management procedures to address the buffer overflow condition in splitvt versions prior to 1.6.4. System administrators should implement comprehensive monitoring to detect unusual login patterns and password-related system calls that might indicate exploitation attempts. The recommended approach involves upgrading to patched versions of splitvt and implementing proper input validation controls to prevent buffer overflows in similar applications. Additionally, security hardening measures such as disabling unnecessary screen locking functions and implementing proper access controls can reduce the attack surface. The vulnerability highlights the importance of input validation and memory safety practices in system utilities, emphasizing that even seemingly benign functions like screen locking can contain critical security flaws that require careful attention and regular security assessments. Organizations should conduct thorough vulnerability assessments to identify similar buffer overflow conditions in other system utilities and applications.