CVE-2017-12702 in WebAccess
Summary
by MITRE
An Externally Controlled Format String issue was discovered in Advantech WebAccess versions prior to V8.2_20170817. String format specifiers based on user provided input are not properly validated, which could allow an attacker to execute arbitrary code.
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Analysis
by VulDB Data Team • 11/12/2019
The vulnerability identified as CVE-2017-12702 represents a critical externally controlled format string flaw within Advantech WebAccess software versions prior to V8.2_20170817. This issue falls under the category of CWE-134 which specifically addresses format string vulnerabilities where format specifiers are derived from external input without proper validation or sanitization. The vulnerability exists in the software's handling of user-provided data that is subsequently used in printf or similar formatting functions, creating a dangerous attack surface where malicious input can manipulate program execution flow.
The technical implementation of this vulnerability allows attackers to inject format specifiers into the application's logging or output functions through user-controlled input fields. When the application processes these inputs without proper validation, it can lead to information disclosure, application crashes, or more critically, arbitrary code execution. The flaw specifically manifests when the software fails to sanitize user-provided strings before using them in format string operations, enabling attackers to craft malicious payloads that exploit the printf family of functions to manipulate memory locations, bypass security mechanisms, or execute unintended code sequences. This type of vulnerability is particularly dangerous in industrial control systems where WebAccess is commonly deployed for SCADA and HMI applications.
The operational impact of this vulnerability extends beyond simple code execution to encompass significant risks for industrial environments. Attackers could potentially gain unauthorized access to critical infrastructure control systems, manipulate operational data, or disrupt manufacturing processes. The vulnerability affects industrial automation systems where WebAccess serves as a web-based interface for monitoring and controlling industrial processes, making it a prime target for advanced persistent threats targeting critical infrastructure. Organizations using affected versions face potential loss of operational integrity, data compromise, and physical system disruption. The attack vector typically involves web-based exploitation through the WebAccess interface where users interact with the system, making it accessible to remote attackers without requiring physical access to the industrial network.
Mitigation strategies for this vulnerability should prioritize immediate software updates to Advantech WebAccess V8.2_20170817 or later versions that contain the necessary patches to address the format string vulnerability. Network segmentation and access controls should be implemented to limit exposure of the affected systems to untrusted networks. Regular security assessments of industrial control systems should include vulnerability scanning for similar format string issues in other industrial software components. Security monitoring should be enhanced to detect anomalous behavior patterns that might indicate exploitation attempts. Organizations should also implement proper input validation mechanisms and conduct security code reviews to prevent similar issues in custom industrial applications. The vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter, as exploitation could involve executing malicious commands through the vulnerable format string functionality. Additionally, the vulnerability demonstrates characteristics of T1190 for exploit public-facing application, as it affects web-accessible industrial control interfaces. Organizations should also consider implementing network intrusion detection systems specifically configured to identify patterns associated with format string exploitation attempts in industrial environments.