CVE-2018-25213 in Local SEH Buffer Overflow
Summary
by MITRE • 03/26/2026
Nsauditor 3.0.28.0 contains a structured exception handling buffer overflow vulnerability that allows local attackers to execute arbitrary code by supplying malicious input to the DNS Lookup tool. Attackers can craft a payload with SEH chain overwrite and inject shellcode through the DNS Query field to achieve code execution with application privileges.
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Analysis
by VulDB Data Team • 05/06/2026
The vulnerability identified as CVE-2018-25213 affects Nsauditor version 3.0.28.0, a network security auditing tool that provides various network scanning and analysis capabilities. This particular flaw resides within the DNS Lookup functionality of the application, making it a critical concern for users who rely on this specific feature for network reconnaissance activities. The vulnerability represents a classic buffer overflow scenario that occurs during structured exception handling operations, specifically when processing DNS query inputs.
The technical implementation of this vulnerability stems from improper input validation within the DNS Lookup tool's handling of user-supplied data. When an attacker provides malicious input through the DNS Query field, the application fails to properly bounds-check the input before processing it through the structured exception handling mechanism. This oversight creates an exploitable condition where the buffer overflow can be leveraged to overwrite the structured exception handler chain, specifically the SEH (Structured Exception Handler) chain that is fundamental to Windows application error handling. The vulnerability is classified as a local privilege escalation vector since it requires local system access to exploit but can execute code with the privileges of the running application.
The operational impact of this vulnerability is significant for organizations using Nsauditor as part of their network security assessment toolkit. Attackers who gain local access to a system running Nsauditor can leverage this vulnerability to execute arbitrary code with the same privileges as the Nsauditor application, typically system-level privileges or at least user-level privileges depending on how the application is configured. This code execution capability allows adversaries to establish persistent access, escalate privileges further, or deploy additional malicious payloads within the network environment. The vulnerability's exploitation requires minimal network interaction since it's a local attack vector, making it particularly dangerous in environments where local system access is possible.
From a cybersecurity framework perspective, this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and CWE-122, which covers heap-based buffer overflows, though the specific implementation appears to involve structured exception handling. The attack pattern follows techniques described in the MITRE ATT&CK framework under T1059 for command and scripting interpreter and T1068 for exploit for privilege escalation. The SEH chain overwrite technique employed in this exploitation is a well-documented method in exploit development that has been used across numerous Windows applications, making it a familiar attack vector for threat actors. Organizations should implement immediate mitigations including applying the vendor-provided patch, restricting local system access to systems running Nsauditor, and monitoring for suspicious execution patterns that might indicate exploitation attempts.
The remediation approach for this vulnerability requires the immediate application of the security patch provided by the vendor to address the buffer overflow in the DNS Lookup functionality. Additionally, system administrators should implement principle of least privilege controls to limit local access to systems running Nsauditor, as well as conduct regular security assessments to identify other potentially vulnerable applications within the network infrastructure. Network segmentation and monitoring solutions should be enhanced to detect anomalous behavior patterns that might indicate exploitation attempts, particularly focusing on code execution activities within the context of the Nsauditor process. The vulnerability demonstrates the critical importance of input validation and proper memory management in security-critical applications, highlighting the need for comprehensive security testing throughout the software development lifecycle.