CVE-2017-16753 in WebAccess
Summary
by MITRE
An Improper Input Validation issue was discovered in Advantech WebAccess versions prior to 8.3. WebAccess allows some inputs that may cause the program to crash.
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Analysis
by VulDB Data Team • 12/19/2019
The vulnerability identified as CVE-2017-16753 represents a critical improper input validation flaw within Advantech WebAccess software versions prior to 8.3. This issue stems from insufficient validation mechanisms that fail to properly sanitize or verify user-supplied inputs before processing them within the application. The vulnerability manifests when the software accepts malformed or unexpected input data that can trigger unexpected program behavior, ultimately leading to application crashes or potential system instability. The root cause aligns with CWE-20, which specifically addresses improper input validation, a fundamental security weakness that occurs when applications fail to adequately validate, sanitize, or escape input data before processing. This weakness creates an attack surface where malicious actors can exploit the lack of proper input validation to disrupt service availability and potentially escalate their attacks.
The technical exploitation of this vulnerability demonstrates how unvalidated inputs can be leveraged to cause denial of service conditions within the WebAccess environment. When the application processes inputs without proper validation, it becomes susceptible to various malformed data sequences that can trigger memory corruption, buffer overflows, or other internal processing errors. The impact extends beyond simple crashes to potentially create conditions that could allow for more sophisticated attacks, particularly when combined with other vulnerabilities or attack vectors within the broader system landscape. This type of vulnerability is particularly concerning in industrial control systems where WebAccess is commonly deployed, as it can disrupt critical operations and create security gaps that adversaries might exploit to gain further access to the industrial network infrastructure.
From an operational standpoint, the vulnerability presents significant risks to organizations relying on Advantech WebAccess for industrial automation and monitoring purposes. The ability to cause application crashes through improper input validation can result in service interruptions that directly impact operational efficiency and potentially lead to safety concerns in industrial environments where continuous operation is critical. The vulnerability's impact is amplified in environments where WebAccess serves as a central component of industrial control systems, as disruptions can cascade across multiple connected devices and processes. Organizations using affected versions of WebAccess should consider the potential for both intentional exploitation and accidental system instability that could result from legitimate but improperly formatted inputs. The vulnerability's classification under ATT&CK technique T1499.004, which covers network denial of service, demonstrates how this weakness can be leveraged to create service disruption conditions that align with broader cyberattack objectives.
The recommended mitigation strategies for CVE-2017-16753 focus primarily on upgrading to Advantech WebAccess version 8.3 or later, which includes proper input validation mechanisms and enhanced security controls. Organizations should also implement network segmentation and access controls to limit exposure of affected systems to untrusted networks or users. Additional defensive measures include deploying intrusion detection systems to monitor for anomalous input patterns and implementing robust input filtering at network boundaries. Security teams should conduct comprehensive vulnerability assessments to identify all instances of affected WebAccess installations and ensure proper patch management procedures are in place to maintain system integrity. The remediation approach should also include reviewing and updating system configurations to minimize the attack surface and implementing monitoring procedures that can detect potential exploitation attempts. Organizations should also consider implementing application whitelisting controls and restricting user privileges to limit the potential impact of successful exploitation attempts.