CVE-2019-25591 in DNSS Domain Name Search Software
Summary
by MITRE • 03/22/2026
DNSS Domain Name Search Software 2.1.8 contains a buffer overflow vulnerability in the registration code input field that allows local attackers to crash the application by submitting an excessively long string. Attackers can trigger a denial of service by pasting a malicious registration code containing 300 repeated characters into the Name/Key field via the Register menu option.
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Analysis
by VulDB Data Team • 03/25/2026
The DNSS Domain Name Search Software version 2.1.8 presents a critical buffer overflow vulnerability that fundamentally compromises the application's memory integrity and operational stability. This vulnerability exists within the registration code input processing mechanism, specifically targeting the Name/Key field validation routine. The flaw represents a classic stack-based buffer overflow condition where insufficient input length validation permits attackers to exceed the allocated memory buffer boundaries. The vulnerability manifests when the application processes registration codes exceeding normal parameter limits, creating a scenario where malicious input can overwrite adjacent memory segments and corrupt the program's execution flow. Such buffer overflow conditions typically arise from improper bounds checking and lack of input sanitization mechanisms within the software's registration subsystem.
The technical exploitation of this vulnerability occurs through a straightforward yet effective method involving the submission of an extraordinarily long registration code string containing 300 repeated characters. This specific attack vector demonstrates the software's failure to implement proper input length constraints and memory boundary validation during the registration process. When users navigate to the Register menu option and paste the malicious registration code into the Name/Key field, the application's insufficient input validation allows the oversized string to be processed without adequate buffer size checking. The overflow occurs because the application allocates a fixed-size buffer for registration code processing but fails to verify that incoming data adheres to predefined length limits. This vulnerability directly maps to CWE-121 Stack-based Buffer Overflow, which classifies buffer overflows occurring in stack memory regions due to inadequate bounds checking.
The operational impact of this vulnerability extends beyond simple application instability, creating significant risks for system availability and service continuity. Local attackers can reliably trigger a denial of service condition by exploiting this buffer overflow, causing the DNSS Domain Name Search Software to crash and terminate unexpectedly. The crash behavior represents a complete denial of service scenario where legitimate users cannot access the registration functionality or utilize the core domain name search capabilities. This vulnerability particularly affects environments where the software serves as a critical component for domain name resolution and network services, as the application's instability can cascade into broader system availability issues. The local privilege requirement indicates that while the vulnerability is accessible to users with system access, it still presents a substantial risk to system integrity and availability. According to ATT&CK framework, this vulnerability aligns with T1499.004 Network Denial of Service, as it specifically targets application availability through buffer overflow exploitation techniques.
Mitigation strategies for this vulnerability must address both immediate remediation and long-term architectural improvements to prevent similar issues. The most effective immediate solution involves implementing strict input length validation and buffer size enforcement within the registration code processing routine. Software developers should establish maximum character limits for registration fields and implement robust input sanitization mechanisms that reject oversized inputs before processing begins. Additionally, memory safety improvements such as stack canaries, address space layout randomization, and heap-based buffer overflow protections should be considered for enhanced defense-in-depth. The vulnerability also highlights the importance of proper software testing including fuzz testing and boundary condition validation to identify similar memory corruption issues. Regular security updates and patches should be implemented to address the root cause of the buffer overflow, while system administrators should monitor for signs of exploitation attempts and maintain proper logging of registration activities to detect potential malicious use of this vulnerability.