CVE-2000-1028 in HP-UX
Summary
by MITRE
Buffer overflow in cu program in HP-UX 11.0 may allow local users to gain privileges via a long -l command line argument.
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Analysis
by VulDB Data Team • 09/30/2024
The vulnerability identified as CVE-2000-1028 represents a critical buffer overflow flaw within the cu program on HP-UX 11.0 systems. This issue manifests when the cu utility processes command line arguments, specifically the -l flag, which is used for specifying login names during remote terminal connections. The buffer overflow occurs due to insufficient input validation and bounds checking in the argument parsing mechanism, creating a scenario where malicious input can overwrite adjacent memory locations. The cu program, being a fundamental component for establishing serial connections and remote terminal sessions, operates with elevated privileges and is accessible to local users, making this vulnerability particularly dangerous from a privilege escalation perspective. The flaw falls under CWE-121, which categorizes buffer overflow conditions where insufficient boundary checks allow memory to be overwritten beyond allocated buffers. This vulnerability aligns with ATT&CK technique T1068, which covers privilege escalation through local exploits, as local users can leverage this flaw to elevate their privileges to root level.
The technical exploitation of this vulnerability requires a local user to execute the cu program with a specially crafted -l argument that exceeds the allocated buffer size. When the program processes this overly long argument, it writes data beyond the intended memory boundaries, potentially corrupting the stack and allowing an attacker to overwrite return addresses or other critical program variables. The buffer overflow can be leveraged to execute arbitrary code in the context of the cu program's privileges, which typically run with elevated permissions due to the nature of serial communication and remote access operations. The exploitation process involves careful construction of the input to overwrite the instruction pointer or other control flow elements, enabling the execution of malicious code. This particular vulnerability demonstrates how legacy communication utilities in operating systems can contain fundamental security flaws that persist across multiple versions and architectures, especially when security considerations are not thoroughly addressed during the original development phase.
The operational impact of CVE-2000-1028 extends beyond simple privilege escalation to encompass potential system compromise and unauthorized access to sensitive information. Local users who can execute the cu program can exploit this flaw to gain root access, which provides complete control over the system, including the ability to modify system files, install backdoors, or exfiltrate data. The vulnerability is particularly concerning because it operates at the system level without requiring network access or external attack vectors, making it a low-effort, high-impact threat. Organizations running HP-UX 11.0 systems are especially vulnerable as this version predates many modern security mitigations and defensive programming practices that would normally prevent such buffer overflow conditions. The flaw represents a classic example of how insufficient input validation in system utilities can create persistent security weaknesses that remain exploitable for years after initial deployment, highlighting the importance of proper software security reviews and defensive coding practices throughout the software development lifecycle. Security professionals should note that this vulnerability demonstrates the critical need for regular security assessments and patch management programs to address such long-standing issues in system software components.