CVE-2017-16732 in WebAccess
Summary
by MITRE
A use-after-free issue was discovered in Advantech WebAccess versions prior to 8.3. WebAccess allows an unauthenticated attacker to specify an arbitrary address.
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Analysis
by VulDB Data Team • 12/22/2019
The vulnerability identified as CVE-2017-16732 represents a critical use-after-free flaw in Advantech WebAccess software versions prior to 8.3. This type of vulnerability occurs when a program continues to reference memory after it has been freed, creating a potential exploitation vector for malicious actors. The issue specifically affects the web-based interface component of Advantech WebAccess, which is commonly used in industrial automation and monitoring environments. The vulnerability allows an unauthenticated attacker to specify an arbitrary memory address, potentially enabling remote code execution or system compromise. This flaw falls under the CWE-416 category of Use After Free, which is classified as a serious weakness in software security practices. The vulnerability exists due to inadequate memory management within the application's handling of user-supplied input through the web interface, where the program fails to properly validate or sanitize memory references before allowing external input to manipulate memory addresses. The operational impact of this vulnerability extends beyond simple exploitation as it affects industrial control systems where WebAccess is deployed for supervisory control and data acquisition. Attackers could leverage this vulnerability to gain unauthorized access to critical infrastructure monitoring systems, potentially disrupting operations or gaining persistent access to industrial networks. The lack of authentication requirements makes this particularly dangerous as it requires no credentials to exploit, aligning with ATT&CK technique T1210 for exploiting known vulnerabilities in target systems. Organizations using Advantech WebAccess in operational technology environments face significant risk as this vulnerability could enable attackers to manipulate industrial processes or access sensitive operational data.
The technical exploitation of CVE-2017-16732 involves an attacker sending specially crafted input to the WebAccess web interface that triggers the use-after-free condition. When the application processes this input, it frees memory associated with a specific object but continues to reference that memory location, creating a scenario where arbitrary memory addresses can be manipulated. This allows attackers to potentially overwrite memory contents, redirect program execution flow, or inject malicious code into the running process. The vulnerability's impact is amplified by the fact that it affects a web-accessible interface, making it remotely exploitable from any network location. The flaw demonstrates poor input validation and memory management practices that violate fundamental security principles outlined in industry standards such as the OWASP Top Ten and NIST cybersecurity frameworks. The specific nature of the vulnerability suggests that the application's memory allocation and deallocation routines do not properly track object references, creating opportunities for attackers to manipulate the program's execution flow. This type of vulnerability is particularly concerning in industrial environments where continuous operation and reliability are paramount, as exploitation could lead to system crashes, data corruption, or unauthorized control of critical processes.
Mitigation strategies for CVE-2017-16732 primarily focus on upgrading to Advantech WebAccess version 8.3 or later, which includes patches addressing the use-after-free condition. Organizations should also implement network segmentation to limit access to WebAccess interfaces, particularly in industrial environments where such systems are deployed. Access controls should be enforced through proper authentication mechanisms and network firewalls to restrict external exposure of the vulnerable web interface. Regular security assessments and vulnerability scanning should be conducted to identify any remaining instances of older WebAccess versions within the industrial control network. The implementation of intrusion detection systems can help monitor for suspicious network traffic patterns that may indicate exploitation attempts. Additionally, organizations should consider implementing application whitelisting policies and maintaining up-to-date security patches across all industrial control system components. The vulnerability highlights the importance of secure coding practices and proper memory management in industrial software development, emphasizing the need for regular security reviews and code audits to prevent similar issues in future releases. Network monitoring solutions should be configured to detect and alert on unusual memory access patterns that might indicate exploitation attempts. Organizations should also develop incident response procedures specifically addressing industrial control system vulnerabilities to ensure rapid response to potential exploitation events.