CVE-2008-0763 in Network Print Server
Summary
by MITRE
Stack-based buffer overflow in NPSpcSVR.exe in Larson Network Print Server (LstNPS) 9.4.2 build 105 and earlier allows remote attackers to execute arbitrary code via a long argument in a LICENSE command on TCP port 3114.
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Analysis
by VulDB Data Team • 11/07/2017
The vulnerability identified as CVE-2008-0763 represents a critical stack-based buffer overflow in the NPSpcSVR.exe component of Larson Network Print Server version 9.4.2 build 105 and earlier. This flaw exists within the network print server software that facilitates printing services over network connections, specifically targeting the licensing command interface that operates on TCP port 3114. The vulnerability arises from insufficient input validation when processing client-supplied arguments in the LICENSE command, creating an exploitable condition that can be leveraged by remote attackers without authentication requirements.
The technical implementation of this vulnerability stems from improper bounds checking within the NPSpcSVR.exe process when handling user-provided data in the LICENSE command execution flow. When a remote attacker sends a specially crafted packet containing an excessively long argument string to the TCP port 3114, the application fails to properly validate the input length against the allocated stack buffer size. This results in memory corruption that overwrites adjacent stack memory locations, potentially allowing an attacker to overwrite return addresses and function pointers with malicious code pointers. The vulnerability specifically maps to CWE-121 Stack-based Buffer Overflow, which is classified as a fundamental memory safety issue in software development practices.
The operational impact of this vulnerability extends beyond simple remote code execution capabilities, as it fundamentally compromises the integrity and availability of the network print server infrastructure. Attackers can leverage this vulnerability to gain arbitrary code execution privileges on the affected system, potentially escalating their access to full system control. This creates a significant risk for organizations relying on print server services, as unauthorized code execution could lead to data exfiltration, persistent backdoor installation, or further network infiltration through compromised print server systems. The vulnerability's remote exploitability means that attackers do not require physical access or local network presence to compromise the system, making it particularly dangerous in enterprise environments where print servers often serve multiple departments and locations.
The attack surface for this vulnerability encompasses any organization using Larson Network Print Server versions 9.4.2 build 105 or earlier, particularly those with exposed TCP port 3114 or systems that have not implemented proper network segmentation. From an ATT&CK framework perspective, this vulnerability maps to techniques involving remote code execution and privilege escalation, with potential for lateral movement within networks where print servers are integrated into broader infrastructure. Organizations should prioritize immediate patching of affected systems, as the vulnerability has been widely documented and exploited in various threat actor campaigns targeting enterprise print server infrastructure. Network administrators should also consider implementing firewall rules to restrict access to TCP port 3114 from untrusted networks while monitoring for suspicious traffic patterns that may indicate exploitation attempts. Additionally, the vulnerability highlights the importance of regular security assessments and vulnerability management processes to identify and remediate similar issues in legacy network services that may not receive ongoing security support from vendors.