CVE-2016-20050 in NetSchedScan
Summary
by MITRE • 04/04/2026
NetSchedScan 1.0 contains a buffer overflow vulnerability in the scan Hostname/IP field that allows local attackers to crash the application by supplying an oversized input string. Attackers can paste a crafted payload containing 388 bytes of data followed by 4 bytes of EIP overwrite into the Hostname/IP field to trigger a denial of service condition.
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Analysis
by VulDB Data Team • 07/21/2026
The vulnerability identified as CVE-2016-20050 represents a critical buffer overflow flaw within NetSchedScan version 1.0, a network scanning utility designed for host discovery and enumeration. This vulnerability specifically targets the application's handling of input data in the Hostname/IP field, exposing a fundamental security weakness that can be exploited by local attackers to disrupt system operations. The flaw demonstrates poor input validation and memory management practices that are commonly associated with software development security gaps. The vulnerability exists within the application's parsing logic where insufficient bounds checking allows arbitrary data to be written beyond the allocated buffer space, creating an exploitable condition that can lead to application instability and potential system compromise.
The technical implementation of this buffer overflow occurs when the application processes user-supplied input in the Hostname/IP field without proper size validation or boundary checking mechanisms. Attackers can craft a specific payload consisting of 388 bytes of arbitrary data followed by 4 bytes intended to overwrite the instruction pointer register EIP, effectively redirecting program execution flow. This particular exploitation technique leverages the classic stack-based buffer overflow methodology where the overflow corrupts the return address on the stack, allowing malicious code execution or program termination. The vulnerability classification aligns with CWE-121, which describes stack-based buffer overflow conditions, and CWE-122, which addresses heap-based buffer overflow scenarios that can occur in similar applications. The specific 408-byte payload structure indicates a precise understanding of the target application's memory layout and stack organization, suggesting either advanced exploitation knowledge or the presence of detailed vulnerability analysis tools.
The operational impact of this vulnerability extends beyond simple denial of service conditions, as it provides local attackers with a mechanism to potentially execute arbitrary code within the application's execution context. When the malformed input is processed, the application crashes due to memory corruption, resulting in a denial of service that can disrupt legitimate network scanning operations. The vulnerability affects the availability and reliability of the NetSchedScan utility, potentially causing network administrators to lose access to critical discovery tools during security assessments or routine network maintenance activities. From an operational security perspective, this vulnerability represents a significant risk to systems where local users have access to the application, as it allows for privilege escalation opportunities or system compromise. The vulnerability also exposes potential information disclosure risks if the buffer overflow can be leveraged to extract memory contents or system information through controlled crashes and memory dumps.
Mitigation strategies for CVE-2016-20050 should focus on immediate application patching and input validation enhancements. The most effective remediation involves updating to a patched version of NetSchedScan that implements proper bounds checking and input sanitization mechanisms. Organizations should implement defensive programming practices including stack canaries, address space layout randomization, and heap metadata protection to reduce exploitability. The application should enforce strict input length limits and validate all user-supplied data before processing, implementing proper buffer management techniques such as those recommended in the OWASP Secure Coding practices. Network segmentation and access controls should be implemented to limit local user access to privileged applications, reducing the attack surface for local exploitation. Additionally, security monitoring should be enhanced to detect abnormal application behavior or crash patterns that may indicate exploitation attempts, utilizing intrusion detection systems and application behavior monitoring tools to identify potential exploitation activities. The vulnerability also highlights the importance of regular security assessments and code reviews to identify similar memory corruption issues in legacy applications that may not have been designed with modern security considerations in mind.