CVE-2017-9558 in Mobile App
Summary
by MITRE
The wawa-employees-credit-union-mobile/id1158082793 app 4.0.1 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.
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Analysis
by VulDB Data Team • 10/18/2019
The vulnerability identified as CVE-2017-9558 affects the wawa-employees-credit-union-mobile iOS application version 4.0.1, presenting a critical security flaw in the mobile banking ecosystem. This issue represents a fundamental failure in the application's secure communication implementation, specifically within its SSL/TLS certificate verification mechanisms. The absence of proper X.509 certificate validation creates a significant attack surface that adversaries can exploit to compromise user data and financial transactions. The vulnerability is particularly concerning given that the application handles sensitive financial information for credit union members, making it an attractive target for cybercriminals seeking to intercept and manipulate financial communications.
The technical flaw manifests as a complete absence of SSL certificate validation within the application's network communication stack. When the iOS application establishes connections to backend servers, it fails to perform the essential X.509 certificate verification process that should confirm the server's identity and ensure the authenticity of the cryptographic keys presented during the TLS handshake. This omission places the application into a state where it will accept any certificate presented by a server, regardless of whether it is issued by a trusted certificate authority, expired, or specifically crafted by an attacker. The vulnerability directly maps to CWE-295, which addresses the improper validation of certificate authorities, and represents a classic example of weak cryptographic implementation that undermines the entire security architecture of the mobile application.
The operational impact of this vulnerability extends far beyond simple data interception, creating multiple attack vectors for man-in-the-middle adversaries who can exploit the weakness to conduct sophisticated attacks against users and the financial institution. Attackers can deploy malicious intermediaries that present forged certificates to the vulnerable application, allowing them to transparently intercept and modify all communications between the mobile client and backend servers. This capability enables unauthorized access to user credentials, transaction details, account balances, and other sensitive financial data. The vulnerability also facilitates session hijacking and transaction manipulation, potentially allowing attackers to redirect funds or alter account information without detection. From an ATT&CK framework perspective, this vulnerability enables techniques such as T1041 (Exfiltration Over C2 Channel) and T1566 (Phishing) by providing a method for attackers to establish persistent access to sensitive information.
Mitigation strategies for CVE-2017-9558 require immediate implementation of proper SSL certificate validation mechanisms within the mobile application. Organizations should implement certificate pinning techniques that validate server certificates against a known set of trusted certificates or public keys, preventing the acceptance of forged certificates even if they appear valid. The application must be updated to perform comprehensive X.509 certificate validation including checking certificate expiration dates, verifying certificate chains, and ensuring certificates are issued by trusted certificate authorities. Additionally, the implementation should include proper error handling for certificate validation failures to prevent the application from continuing operations with unverified connections. Security testing should include comprehensive penetration testing of network communication components and regular security audits to ensure that cryptographic implementations remain robust against evolving attack techniques. The vulnerability also necessitates updates to the application's security policies and procedures, ensuring that all network communications are properly secured and that developers follow secure coding practices for mobile application development.