CVE-2016-7812 in App
Summary
by MITRE
The Bank of Tokyo-Mitsubishi UFJ, Ltd. App for Android ver5.3.1, ver5.2.2 and earlier allow a man-in-the-middle attacker to downgrade the communication between the app and the server from TLS v1.2 to SSL v3.0, which may result in the attacker to eavesdrop on an encrypted communication.
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Analysis
by VulDB Data Team • 01/07/2021
The vulnerability identified as CVE-2016-7812 affects the Bank of Tokyo-Mitsubishi UFJ mobile banking application for android systems version 5.3.1 and earlier. This security flaw represents a critical downgrade attack vector that specifically targets the cryptographic communication protocols used between the mobile client and the banking server infrastructure. The vulnerability manifests when the application fails to properly enforce secure communication channel establishment, allowing malicious actors positioned within the network to manipulate the TLS negotiation process and force the system to utilize older, less secure cryptographic protocols.
The technical implementation of this vulnerability stems from improper protocol version negotiation within the application's secure communication stack. When establishing connections to the banking server, the application does not adequately validate or enforce the use of modern cryptographic standards. Specifically, the system allows downgrade attacks that force communication to revert from TLS version 1.2 down to SSL version 3.0, which represents a significant security regression. SSL v3.0 contains known cryptographic weaknesses and has been deprecated for years due to its susceptibility to various attacks including POODLE and other protocol-level vulnerabilities. This downgrade mechanism creates an exploitable condition where an attacker can intercept and potentially decrypt sensitive financial transactions and personal data transmitted between the mobile application and the banking infrastructure.
The operational impact of this vulnerability extends beyond simple data eavesdropping to encompass complete compromise of the application's security posture. Financial data, user credentials, transaction details, and personal identification information could be intercepted and decrypted by attackers positioned within the network. The vulnerability directly violates industry security standards and best practices, particularly those outlined in the OWASP Mobile Security Project which emphasizes the importance of secure communication protocols and proper cryptographic implementation. From an attack perspective, this vulnerability aligns with ATT&CK technique T1041 for Exfiltration Over C2 Channel, and T1566 for Phishing, as it enables attackers to establish persistent access to sensitive banking information. The risk is amplified because the application serves as a primary interface for financial transactions, making any compromise potentially devastating to both individual users and the financial institution's reputation and regulatory compliance status.
Mitigation strategies for this vulnerability must address both immediate remediation and long-term architectural improvements. The primary fix involves implementing proper TLS version enforcement within the application's communication stack, ensuring that only modern cryptographic protocols are accepted during connection establishment. This includes implementing protocol version pinning and disabling support for deprecated SSL versions. Additionally, the application should implement certificate pinning mechanisms to prevent man-in-the-middle attacks that could manipulate certificate validation. Security headers and proper HTTP security configurations should be implemented to prevent downgrade attacks. Organizations should also conduct regular security testing including TLS protocol validation, network traffic analysis, and penetration testing to identify similar vulnerabilities. The remediation process should follow NIST SP 800-52 guidelines for cryptographic standards and ensure compliance with PCI DSS requirements for secure financial transactions. Regular security updates and patch management procedures should be implemented to prevent similar vulnerabilities from being introduced in future versions of the mobile banking application.