CVE-2000-0775 in Viking Server
Summary
by MITRE
Buffer overflow in RobTex Viking server earlier than 1.06-370 allows remote attackers to cause a denial of service or execute arbitrary commands via a long HTTP GET request, or long Unless-Modified-Since, If-Range, or If-Modified-Since headers.
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Analysis
by VulDB Data Team • 10/12/2025
The vulnerability identified as CVE-2000-0775 represents a critical buffer overflow condition within the RobTex Viking web server software, specifically affecting versions prior to 1.06-370. This flaw resides in the server's handling of HTTP request headers and can be exploited by remote attackers to either disrupt service availability or gain unauthorized command execution capabilities. The vulnerability manifests when the server processes malformed HTTP GET requests containing excessively long header values, particularly the Unless-Modified-Since, If-Range, or If-Modified-Since headers that exceed the allocated buffer space. Such buffer overflows typically occur when input validation is insufficient and the server fails to properly bounds-check incoming data before copying it into fixed-size memory buffers.
The technical nature of this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and CWE-122, which covers heap-based buffer overflow scenarios. The attack vector involves sending specially crafted HTTP requests containing header values that exceed the maximum buffer capacity, causing memory corruption that can lead to unpredictable behavior. When the buffer overflow occurs, it can overwrite adjacent memory locations including return addresses, potentially allowing attackers to redirect program execution flow and execute arbitrary code with the privileges of the web server process. This represents a significant security risk as the server typically runs with elevated privileges to serve web content and manage system resources.
From an operational impact perspective, this vulnerability creates a serious threat to system availability and integrity. The denial of service component can render the web server completely unresponsive to legitimate requests, effectively taking critical web services offline and disrupting business operations. Additionally, the remote code execution capability allows attackers to potentially gain complete control over the affected server, enabling them to install malware, steal sensitive data, or use the compromised system as a launch point for further attacks within the network infrastructure. The vulnerability is particularly dangerous because it requires no authentication to exploit and can be executed from any network location, making it a prime target for automated scanning and exploitation tools.
The attack surface for this vulnerability extends across all systems running affected versions of the RobTex Viking server software, particularly those exposed to the internet or accessible from untrusted networks. Security practitioners should consider this vulnerability in the context of ATT&CK technique T1210, which covers exploitation of remote services, and T1499, which covers network denial of service attacks. Organizations should implement immediate mitigations including updating to RobTex Viking version 1.06-370 or later, which contains the necessary patches to prevent buffer overflow conditions in header processing. Network segmentation and firewall rules can provide additional protection by limiting access to the vulnerable web server, while intrusion detection systems can monitor for suspicious HTTP request patterns that may indicate exploitation attempts. Regular security assessments and vulnerability scanning should be conducted to identify any other potentially affected systems running legacy versions of the software, as this type of buffer overflow vulnerability often indicates broader code quality issues that may present additional security risks.