CVE-2026-113363 in WebSAM WinShare
Summary
by MITRE • 11/09/2026
Improper Input Validation in the network communication processing in NEC Corporation WebSAM WinShare Ver 7.2.0 through 7.5.0, Ver 7.6.0 and Ver 7.7.0 through 7.7.2 on Windows allows a remote unauthenticated attacker to execute arbitrary commands with SYSTEM privileges via a crafted network packet sent to the computer on which WinShare is running.
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Analysis
by VulDB Data Team • 11/09/2026
The vulnerability identified in NEC Corporation WebSAM WinShare versions 7.2.0 through 7.5.0, as well as version 7.6.0 and versions 7.7.0 through 7.7.2 on Windows platforms, represents a critical failure in input validation within the network communication processing module. This flaw allows remote unauthenticated attackers to execute arbitrary commands with SYSTEM privileges by sending specially crafted network packets to the affected system. The core technical issue stems from insufficient sanitization and verification of data received over the network before it is processed by the application logic. When a maliciously constructed packet arrives, the software fails to properly validate the structure, length, or content of specific fields within that packet. This lack of rigorous checking enables an attacker to inject shell commands or exploit buffer handling mechanisms directly into the execution context of the service running on the host machine.
From a technical perspective, this vulnerability is classified under CWE-20 Improper Input Validation and often involves elements of CWE-78 OS Command Injection when the flaw leads to command execution. The absence of proper boundary checks or type enforcement allows an attacker to bypass expected data formats and inject executable payloads into system-level processes. Since WebSAM WinShare handles network communications for asset management, it likely operates with elevated privileges to perform discovery scans, agent installations, or configuration updates across a corporate network. This architectural design choice amplifies the severity of the vulnerability because any successful exploitation results in full control over the operating system rather than just access within an isolated application sandbox.
The operational impact of this vulnerability is severe due to its remote and unauthenticated nature. An attacker does not need valid credentials or prior access to exploit this flaw, making it highly attractive for automated scanning tools used by threat actors seeking widespread compromise. Once executed with SYSTEM privileges, the attacker gains complete control over the compromised host. This includes the ability to install backdoors, create new administrative accounts, exfiltrate sensitive data stored on the server, and pivot further into the internal network using this machine as a foothold. In an enterprise environment where WebSAM is deployed for IT asset management, compromising such a central node can lead to widespread disruption of inventory tracking, patch management workflows, and potentially expose other connected systems that rely on trust relationships with the compromised WinShare server.
This vulnerability aligns with MITRE ATT&CK technique T1059 Command and Scripting Interpreter, specifically regarding how attackers leverage system utilities or injected commands to achieve their objectives after initial access is gained through network-based exploitation. The attack vector falls under Remote Code Execution via Network Protocol, which is a common pattern in legacy enterprise software that prioritizes connectivity over strict security boundaries. Attackers can exploit this by crafting packets with specific malformed headers or payload structures designed to trigger the input validation failure and subsequently execute system commands such as net user additions, file downloads using tools like certutil or powershell, or reverse shell connections back to a command-and-control server.
Mitigation strategies must focus on immediate patching and network-level controls until updates are applied. NEC Corporation has released patches for the affected versions, so organizations should prioritize upgrading WebSAM WinShare to version 7.5.1, 7.6.1, or 7.7.3 and later where these input validation flaws have been corrected. In environments where immediate patching is not feasible due to operational constraints, network segmentation is critical. The WinShare server should be isolated in a dedicated management VLAN with strict firewall rules that restrict inbound traffic on the vulnerable ports to only authorized IP addresses from trusted administration workstations or other verified asset discovery sources. Additionally, deploying intrusion detection systems configured to detect anomalous packet structures or known exploit signatures related to this vulnerability can provide an additional layer of defense by blocking malicious packets before they reach the application logic. Regular auditing of network traffic and ensuring that all services running with high privileges adhere to the principle of least privilege will further reduce the blast radius if a similar vulnerability is discovered in the future.