CVE-2017-7909 in MESR901
Summary
by MITRE
A Use of Client-Side Authentication issue was discovered in Advantech B+B SmartWorx MESR901 firmware versions 1.5.2 and prior. The web interface uses JavaScript to check client authentication and redirect unauthorized users. Attackers may intercept requests and bypass authentication to access restricted web pages.
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Analysis
by VulDB Data Team • 09/24/2020
The vulnerability identified as CVE-2017-7909 represents a critical client-side authentication flaw in Advantech B+B SmartWorx MESR901 firmware versions 1.5.2 and earlier. This issue stems from the improper implementation of authentication mechanisms within the device's web interface, where the system relies on JavaScript-based validation rather than robust server-side authentication controls. The flaw allows attackers to manipulate client-side code and bypass the intended access controls that should restrict unauthorized users from accessing sensitive administrative functions.
The technical nature of this vulnerability falls under CWE-604, which specifically addresses the use of client-side authentication in a manner that can be easily circumvented by attackers. The web interface employs JavaScript to perform authentication checks and redirect users based on their access level, creating a fundamental security weakness where the authentication logic exists entirely on the client side. This approach violates core security principles as it places trust in client-side code that can be modified, inspected, or intercepted by malicious actors. The JavaScript-based validation serves as a false sense of security since it can be easily bypassed through manual request manipulation or interception techniques.
From an operational perspective, this vulnerability creates significant risks for industrial control systems and manufacturing environments that rely on Advantech MESR901 devices. Attackers who successfully exploit this weakness can gain unauthorized access to administrative interfaces, potentially leading to system compromise, data manipulation, or disruption of critical manufacturing processes. The ability to intercept and modify requests allows threat actors to directly access restricted web pages without proper authorization, undermining the integrity and confidentiality of the industrial network. This vulnerability particularly impacts environments where operational technology and information technology systems intersect, creating potential attack vectors that could affect production operations and safety protocols.
The mitigation strategies for CVE-2017-7909 should focus on implementing proper server-side authentication controls and eliminating reliance on client-side validation for security-critical operations. Organizations should upgrade to firmware versions that address this vulnerability, as Advantech has released updates to correct the authentication implementation. Network segmentation and additional access controls should be implemented to limit exposure, while security monitoring should be enhanced to detect unauthorized access attempts. The vulnerability demonstrates the importance of following security best practices such as those outlined in the OWASP Top Ten and NIST cybersecurity frameworks, which emphasize the need for robust server-side validation and proper authentication mechanisms. Additionally, implementing network-level controls and intrusion detection systems can help identify and prevent exploitation attempts, while regular security assessments should verify that authentication mechanisms are properly implemented and functioning as intended.