CVE-2017-6025 in CODESYS Web Server
Summary
by MITRE
A Stack Buffer Overflow issue was discovered in 3S-Smart Software Solutions GmbH CODESYS Web Server. The following versions of CODESYS Web Server, part of the CODESYS WebVisu web browser visualization software, are affected: CODESYS Web Server Versions 2.3 and prior. A malicious user could overflow the stack buffer by providing overly long strings to functions that handle the XML. Because the function does not verify string size before copying to memory, the attacker may then be able to crash the application or run arbitrary code.
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Analysis
by VulDB Data Team • 12/25/2020
The CVE-2017-6025 vulnerability represents a critical stack buffer overflow flaw within the CODESYS Web Server component of 3S-Smart Software Solutions GmbH's CODESYS WebVisu web browser visualization software. This vulnerability specifically affects versions 2.3 and earlier, creating a significant security risk for industrial control systems and embedded web applications that rely on this software for visualization and web-based access. The flaw resides in the XML processing functionality where input validation is insufficient, allowing attackers to exploit memory corruption through malformed string inputs that exceed buffer boundaries.
The technical implementation of this vulnerability stems from improper input validation within the XML handling functions of the web server component. When the system processes XML data containing excessively long strings, the buffer overflow occurs because the software fails to perform adequate bounds checking before copying data into fixed-size memory buffers. This classic buffer overflow condition allows an attacker to overwrite adjacent memory locations, potentially corrupting program execution flow and creating opportunities for arbitrary code execution. The vulnerability operates at the application layer and can be triggered through web-based interactions with the visualization server.
The operational impact of this vulnerability extends beyond simple application crashes to potentially enable full system compromise in environments where CODESYS Web Server is deployed. Industrial control systems, supervisory control and data acquisition systems, and embedded web applications that utilize this visualization software become vulnerable to remote code execution attacks. Attackers could leverage this vulnerability to gain unauthorized access to control systems, disrupt operations, or potentially cause physical damage to industrial processes. The attack surface is particularly concerning in critical infrastructure environments where such visualization tools are commonly deployed.
Mitigation strategies for CVE-2017-6025 should prioritize immediate version upgrades to CODESYS Web Server 2.4 or later, which contain the necessary patches to address the buffer overflow vulnerability. Organizations should also implement network segmentation to limit access to affected systems, disable unnecessary web services, and deploy intrusion detection systems to monitor for exploitation attempts. The vulnerability aligns with CWE-121 Stack-based Buffer Overflow, which is classified under the broader category of buffer overflow vulnerabilities in software systems. From an attack framework perspective, this vulnerability would map to techniques in the execution and privilege escalation phases of the ATT&CK matrix, potentially enabling lateral movement within industrial control networks. Regular security assessments and vulnerability scanning should be implemented to identify similar issues in legacy industrial software components that may not receive regular updates.