CVE-2017-9569 in On-the-Go App
Summary
by MITRE
The Citizens Bank (TX) cbtx-on-the-go/id892396102 app 3.0.0 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-2017-9569 affects the Citizens Bank cbtx-on-the-go mobile application version 3.0.0 for iOS devices, representing a critical security flaw in the application's cryptographic implementation. This issue stems from the application's failure to properly validate X.509 certificates during SSL/TLS communications, creating a significant attack surface that undermines the fundamental security guarantees of secure network communications. The flaw directly impacts the application's ability to establish trust with backend servers, leaving users vulnerable to sophisticated man-in-the-middle attacks that can compromise sensitive financial data.
The technical implementation of this vulnerability manifests as a complete absence of certificate pinning or validation mechanisms within the mobile application's secure communication stack. When the application establishes connections to Citizens Bank's servers, it fails to perform the essential X.509 certificate verification steps that should confirm the authenticity of the server's identity. This includes checking certificate validity periods, verifying certificate authorities, and ensuring proper certificate chains. The absence of these security controls allows attackers to present fraudulent certificates that appear legitimate to the application, effectively bypassing the entire SSL/TLS security framework designed to protect sensitive financial transactions.
From an operational perspective, this vulnerability creates severe risks for both individual users and the financial institution itself. Attackers can exploit this weakness to intercept and manipulate sensitive financial data, including account balances, transaction histories, and personal identification information. The attack vector typically involves positioning malicious network infrastructure between the user and the bank's servers, allowing the attacker to present a forged certificate that the application accepts without proper validation. This scenario directly violates security principles outlined in the OWASP Mobile Security Project, where the vulnerability maps to the M3 category of Insecure Data Storage and Communication, and aligns with CWE-295 which specifically addresses improper certificate validation.
The impact of this vulnerability extends beyond immediate data theft to encompass long-term security implications for the banking institution's reputation and regulatory compliance. Financial institutions operate under strict regulatory frameworks such as PCI DSS and various banking regulations that mandate robust cryptographic implementations to protect customer data. The absence of certificate validation in this mobile application represents a significant compliance failure that could result in regulatory penalties and legal consequences. Additionally, the vulnerability creates opportunities for credential theft, session hijacking, and other advanced persistent threats that can persist long after the initial compromise, making the attack surface particularly dangerous.
Mitigation strategies for this vulnerability should focus on implementing proper certificate validation mechanisms within the mobile application. This includes implementing certificate pinning techniques that require the application to validate specific certificate fingerprints or public keys, rather than accepting any certificate from a trusted authority. The application should also implement certificate chain validation, proper certificate expiration checking, and robust error handling for validation failures. Organizations should consider implementing additional security controls such as mutual authentication, secure key storage mechanisms, and regular security assessments to prevent similar vulnerabilities in future mobile applications. The remediation process should align with NIST SP 800-52 guidelines for certificate management and incorporate principles from the MITRE ATT&CK framework's network infiltration tactics, particularly focusing on preventing credential access and maintaining persistence through secure communication channels.