CVE-2005-0993 in OpenServer
Summary
by MITRE
Buffer overflow in nwprint in SCO OpenServer 5.0.7 allows local users to execute arbitrary code via a long command line argument.
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Analysis
by VulDB Data Team • 07/07/2018
The vulnerability identified as CVE-2005-0993 represents a critical buffer overflow flaw within the nwprint component of SCO OpenServer 5.0.7 operating system. This issue specifically affects the print spooling functionality that handles command line arguments for print jobs. The buffer overflow occurs when the nwprint utility processes user-supplied command line parameters without adequate bounds checking, creating an exploitable condition that can be leveraged by local attackers to gain elevated privileges and execute arbitrary code on the system. The flaw exists in the handling of print job parameters, where insufficient input validation allows maliciously crafted command line arguments to overwrite adjacent memory regions beyond the allocated buffer space. This vulnerability resides within the system's print subsystem and demonstrates a classic security weakness in software development practices that fail to implement proper input sanitization and boundary checking mechanisms.
The technical implementation of this buffer overflow vulnerability stems from improper memory management within the nwprint utility's argument parsing routine. When local users provide command line arguments exceeding the predetermined buffer size, the excess data overflows into adjacent memory locations, potentially corrupting program execution flow and allowing attackers to inject and execute malicious code. The vulnerability specifically targets the stack-based buffer overflow pattern where the return address or other critical program variables get overwritten by attacker-controlled data. This type of vulnerability falls under the CWE-121 category of stack-based buffer overflow, which is a well-documented weakness in software security that has been extensively categorized and analyzed within the cybersecurity community. The attack vector requires local system access, making it a local privilege escalation vulnerability that could be particularly dangerous in multi-user environments where users might have varying levels of access rights.
The operational impact of CVE-2005-0993 extends beyond simple code execution, as successful exploitation could allow attackers to gain unauthorized access to system resources and potentially escalate privileges to root level. Local users who can execute the nwprint utility with sufficient privileges can leverage this vulnerability to bypass normal security controls and execute malicious payloads with elevated system permissions. The implications are particularly severe in enterprise environments where print services are commonly used and where local users might have access to print spooling functionality. The vulnerability could be exploited to establish persistent backdoors, modify system files, or compromise other services running on the same system. Attackers could potentially use this flaw to create a foothold within the network, especially if the compromised system serves as a print server for multiple users or departments. The vulnerability also aligns with ATT&CK technique T1068 which describes the exploitation of local privilege escalation vulnerabilities to gain higher system privileges.
Mitigation strategies for this vulnerability should include immediate patching of the SCO OpenServer 5.0.7 system with the vendor-provided security update that addresses the buffer overflow condition. System administrators should also implement additional security controls such as restricting local access to the nwprint utility and monitoring print job execution for suspicious command line arguments. The principle of least privilege should be enforced by limiting user access to print spooling functionality and ensuring that only authorized personnel have the ability to execute the affected utility. Network segmentation and access controls can help limit the potential impact if exploitation occurs, while regular security audits and code reviews should be implemented to identify similar buffer overflow vulnerabilities in other system components. Additionally, implementing proper input validation and bounds checking in all system utilities can prevent similar issues from occurring in the future, aligning with security best practices recommended by organizations such as the Open Web Application Security Project and the National Institute of Standards and Technology.