CVE-2003-0061 in HP-UX
Summary
by MITRE
Buffer overflow in passwd for HP UX B.10.20 allows local users to execute arbitrary commands with root privileges via a long LANG environment variable.
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Analysis
by VulDB Data Team • 06/06/2018
The vulnerability described in CVE-2003-0061 represents a critical buffer overflow flaw in the passwd command implementation on HP-UX B.10.20 operating systems. This issue arises from insufficient input validation when processing the LANG environment variable, creating a pathway for local attackers to escalate privileges and execute arbitrary code with root-level permissions. The vulnerability specifically targets the password management utility that is commonly used by system administrators and users to update account credentials, making it a particularly dangerous weakness in the system's security infrastructure.
The technical root cause of this vulnerability stems from improper bounds checking within the passwd command's handling of environment variables. When the system processes the LANG variable, it fails to validate the length of the input data, allowing an attacker to provide an excessively long string that overflows the allocated buffer space. This buffer overflow occurs in the context of the passwd utility execution, which typically runs with elevated privileges due to its role in system authentication management. The flaw follows the common pattern of stack-based buffer overflows where the overflow corrupts adjacent memory regions, potentially allowing an attacker to overwrite return addresses and execute malicious code.
From an operational impact perspective, this vulnerability creates a severe privilege escalation vector that enables local users to gain root access without requiring authentication. The attack requires only local system access and the ability to set environment variables, making it particularly dangerous in multi-user environments where users might have shell access but not administrative privileges. Once exploited, the vulnerability allows attackers to execute arbitrary commands with full system privileges, potentially leading to complete system compromise, data exfiltration, or persistent backdoor installation. The impact extends beyond immediate privilege escalation as it can serve as a foothold for further lateral movement within the network infrastructure.
The vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and represents a classic example of how environment variable handling can create security weaknesses in system utilities. From the ATT&CK framework perspective, this issue maps to privilege escalation techniques through the use of vulnerable system utilities and environment manipulation. The attack vector demonstrates the principle of least privilege violation, where a utility designed for legitimate user authentication purposes becomes a weapon for unauthorized system access. Organizations should note that this vulnerability was particularly concerning in enterprise environments where HP-UX systems were commonly deployed, as it provided a straightforward path to system compromise that required minimal skill or resources to exploit.
Mitigation strategies for this vulnerability include immediate patching of the affected HP-UX systems through official vendor updates, which would address the buffer overflow in the passwd command implementation. System administrators should also implement environment variable restrictions and monitoring to prevent unauthorized manipulation of critical system utilities. Additional defensive measures include enforcing strict privilege separation, implementing regular security audits, and establishing proper access controls to limit local user capabilities. The vulnerability underscores the importance of secure coding practices in system utilities and highlights the need for comprehensive input validation across all system components that handle external data. Organizations should also consider implementing intrusion detection systems to monitor for suspicious environment variable modifications and privilege escalation attempts.