CVE-2017-9576 in Mobile Banking App
Summary
by MITRE
The "Middleton Community Bank Mobile Banking" by Middleton Community Bank app 3.0.0 -- aka middleton-community-bank-mobile-banking/id721843238 for iOS does not verify X.509 certificates from SSL servers, which allows man-in-the-middle attackers to spoof servers and obtain sensitive information via a crafted certificate.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 10/18/2019
The vulnerability identified as CVE-2017-9576 affects the Middleton Community Bank Mobile Banking iOS application version 3.0.0, presenting a critical security flaw in the application's SSL/TLS certificate validation mechanism. This weakness allows attackers to perform man-in-the-middle attacks by presenting crafted certificates that appear legitimate to the mobile banking application. The issue stems from the application's failure to properly validate X.509 certificates during SSL handshakes, creating a significant security gap that undermines the fundamental security assumptions of secure communications.
This vulnerability directly relates to CWE-295, which addresses improper certificate validation in security protocols, and represents a failure in the application's certificate pinning implementation. The absence of proper certificate verification means that attackers can establish fraudulent SSL connections with the mobile banking application, potentially intercepting sensitive user data including login credentials, account information, and financial transactions. The flaw exists at the transport layer security validation point where the application should verify certificate authenticity through trusted certificate authorities or explicit certificate pinning mechanisms.
The operational impact of this vulnerability is severe for both users and the financial institution. Mobile banking users face significant risk of credential theft, financial fraud, and unauthorized account access when conducting transactions through the vulnerable application. Attackers can exploit this weakness to capture and manipulate sensitive data in transit, potentially leading to complete account compromise. The vulnerability affects the confidentiality and integrity of all communications between the mobile application and the bank's servers, undermining the trust model that mobile banking applications must maintain to protect financial data.
Mitigation strategies should focus on implementing proper SSL/TLS certificate validation mechanisms including certificate pinning, explicit certificate verification, and trusted certificate authority validation. The application should be updated to enforce strict certificate validation procedures that align with industry standards such as those recommended in the OWASP Mobile Security Project. Security patches must ensure that the application validates certificate chains against trusted CAs, implements certificate pinning for critical endpoints, and maintains up-to-date certificate trust stores. Additionally, the implementation should follow ATT&CK framework guidance for mobile application security, specifically targeting the T1071.004 technique related to application layer protocol: DNS and T1566.001 technique for credential access through man-in-the-middle attacks. Organizations should conduct comprehensive security testing including penetration testing and vulnerability scanning to ensure the patched implementation properly validates certificates and prevents the exploitation of this class of vulnerability.