CVE-2017-9583 in App
Summary
by MITRE
The "Charlevoix State Bank" by Charlevoix State Bank app 3.0.1 -- aka charlevoix-state-bank/id1128963717 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-2017-9583 affects the Charlevoix State Bank mobile application version 3.0.1 for iOS devices. This represents a critical security flaw in the application's implementation of secure communication protocols, specifically within its handling of SSL/TLS certificate validation. The issue stems from the application's failure to properly validate X.509 certificates presented by SSL servers during secure connections, creating a significant attack surface that compromises the integrity of the communication channel between the mobile client and backend servers.
This vulnerability directly maps to CWE-295, which addresses improper certificate validation in secure communications. The flaw enables man-in-the-middle attacks where adversaries can craft malicious certificates to impersonate legitimate servers within the bank's network infrastructure. The absence of proper certificate verification means that the application accepts any certificate presented by a server without validating its authenticity, trust chain, or cryptographic integrity. This weakness allows attackers to establish fraudulent connections that appear legitimate to the mobile application, potentially capturing sensitive user data including login credentials, account information, and financial transactions.
The operational impact of this vulnerability extends beyond simple data interception, as it fundamentally undermines the security model that mobile banking applications rely upon for protecting customer information. When users interact with the banking application, they expect their communications to be encrypted and authenticated through established trust mechanisms. The vulnerability creates an environment where attackers can transparently intercept and modify data in transit, potentially leading to unauthorized account access, financial fraud, and identity theft. This weakness is particularly dangerous in mobile banking contexts where users may conduct sensitive transactions over public networks, making the attack surface even more expansive.
Mitigation strategies for this vulnerability should focus on implementing proper SSL/TLS certificate validation mechanisms within the application. The fix requires the implementation of certificate pinning, where the application maintains a trusted list of certificate fingerprints or public keys that are explicitly accepted for communication with the bank's servers. Additionally, the application must enforce proper certificate chain validation, including checking certificate expiration dates, verifying certificate authorities, and ensuring the certificate's subject matches the expected server hostname. Organizations should also consider implementing certificate transparency monitoring and regular security assessments to identify and remediate similar issues across their mobile application portfolio. The remediation aligns with ATT&CK technique T1046 which addresses network service scanning and T1566 which covers credential harvesting through social engineering, as this vulnerability enables both network-level attacks and credential theft through man-in-the-middle techniques.