CVE-2017-9593 in Mobile Banking App
Summary
by MITRE
The "Oculina Mobile Banking" by Oculina Bank app 3.0.0 -- aka oculina-mobile-banking/id867025690 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 CVE-2017-9593 vulnerability affects the Oculina Mobile Banking iOS application version 3.0.0, representing a critical security flaw in the mobile banking ecosystem. This vulnerability stems from the application's failure to properly validate X.509 certificates during SSL/TLS connections, creating a significant gap in the security infrastructure that financial institutions rely upon to protect customer data. The flaw specifically impacts the certificate verification process, which is fundamental to establishing trust between mobile banking applications and backend servers. This vulnerability represents a direct violation of security best practices and industry standards that mandate proper certificate validation to prevent unauthorized access and data interception.
The technical implementation of this vulnerability lies in the absence of certificate pinning and proper certificate validation mechanisms within the mobile banking application. When the app establishes SSL connections to banking servers, it fails to validate the server certificates against trusted certificate authorities or implement certificate pinning techniques. This allows attackers to perform man-in-the-middle attacks by presenting forged certificates that appear legitimate to the vulnerable application. The flaw operates at the transport layer security validation, where the application should be verifying certificate chains, expiration dates, and issuer authenticity but instead accepts any certificate presented by the server. This vulnerability directly maps to CWE-295, which specifically addresses improper certificate validation, and aligns with ATT&CK technique T1041, which covers data compression and encryption to avoid detection.
The operational impact of this vulnerability extends far beyond simple security concerns, as it fundamentally compromises the integrity and confidentiality of mobile banking transactions. Attackers exploiting this vulnerability can intercept sensitive customer information including account details, transaction records, and personal identification data during communication with banking servers. The vulnerability enables attackers to establish fake banking server endpoints that appear legitimate to users, potentially leading to unauthorized fund transfers, identity theft, and comprehensive data breaches. Financial institutions face significant regulatory compliance risks, potential legal liability, and reputational damage when such vulnerabilities exist in their mobile banking applications. The attack surface is particularly dangerous because mobile banking applications handle highly sensitive financial data, making this vulnerability an attractive target for cybercriminals seeking financial gain through data theft and fraud.
Mitigation strategies for this vulnerability must address both immediate remediation and long-term security architecture improvements. The primary fix involves implementing proper certificate validation mechanisms, including certificate pinning to specific trusted certificates or certificate authorities. Organizations should deploy certificate validation libraries that properly verify certificate chains, expiration dates, and issuer authenticity before establishing secure connections. Additional security measures include implementing network monitoring to detect unusual certificate behavior and establishing secure communication protocols that require mutual authentication. The solution should also incorporate regular security audits and penetration testing to identify similar validation flaws in other mobile applications. Organizations must align their remediation efforts with industry standards such as NIST SP 800-52 for certificate management and ensure compliance with banking regulatory requirements such as PCI DSS and banking-specific security frameworks. This vulnerability highlights the critical importance of proper SSL/TLS implementation in mobile financial applications and demonstrates why security testing should be integrated throughout the application development lifecycle rather than as an afterthought.