CVE-2003-0840 in HP-UX
Summary
by MITRE
Buffer overflow in dtprintinfo on HP-UX 11.00, and possibly other operating systems, allows local users to gain root privileges via a long DISPLAY environment variable.
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Analysis
by VulDB Data Team • 09/16/2024
The vulnerability identified as CVE-2003-0840 represents a critical buffer overflow flaw in the dtprintinfo utility on HP-UX 11.00 systems and potentially other Unix-like operating systems. This issue arises from inadequate input validation when processing the DISPLAY environment variable, which is commonly used by X Window System applications to specify the display server. The flaw exists within the Desktop Print Info utility that handles printer configuration and print job processing within the HP-UX desktop environment, making it a significant security concern for systems utilizing this specific operating system version.
The technical implementation of this vulnerability stems from the improper handling of environment variables within the dtprintinfo application. When a local user sets an excessively long DISPLAY environment variable, the application fails to properly bounds-check the input data before copying it into a fixed-size buffer. This classic buffer overflow condition occurs because the utility does not validate the length of the DISPLAY variable against the allocated buffer space, allowing malicious input to overwrite adjacent memory locations. The overflow can potentially overwrite return addresses, function pointers, or other critical program state information, enabling arbitrary code execution with elevated privileges.
The operational impact of this vulnerability is severe as it allows local users to escalate their privileges from standard user level to root access without requiring authentication or prior exploitation. This privilege escalation capability means that any user with access to the system can potentially gain complete control over the machine, including access to all files, user accounts, and system resources. The vulnerability affects systems running HP-UX 11.00 and potentially other Unix variants where similar buffer handling flaws exist, making it a widespread concern for organizations maintaining legacy Unix infrastructure. The attack vector requires only local access to the system, which makes it particularly dangerous as it can be exploited by compromised accounts or insiders with legitimate access.
Mitigation strategies for this vulnerability include immediate patching of the affected HP-UX systems with the vendor-provided security updates, which typically involve fixing the buffer overflow in the dtprintinfo utility through proper bounds checking and input validation. System administrators should also implement environment variable restrictions to limit the length of DISPLAY variables that can be set by users, and consider disabling the dtprintinfo utility if it is not essential for system operations. Additionally, implementing proper access controls and monitoring for unusual environment variable modifications can help detect potential exploitation attempts. This vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and relates to ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation' through local system vulnerabilities. Organizations should also conduct comprehensive security assessments to identify similar buffer overflow vulnerabilities in other system utilities and applications that may be susceptible to the same class of attacks.