CVE-2010-4211 in PayPal
Summary
by MITRE
The PayPal app before 3.0.1 for iOS does not verify that the server hostname matches the domain name of the subject of an X.509 certificate, which allows man-in-the-middle attackers to spoof a PayPal web server via an arbitrary certificate.
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Analysis
by VulDB Data Team • 03/19/2015
The vulnerability described in CVE-2010-4211 represents a critical SSL/TLS certificate validation flaw within the PayPal mobile application for iOS versions prior to 3.0.1. This issue stems from the application's failure to properly implement hostname verification during SSL/TLS handshakes, creating a significant security gap that directly violates fundamental cryptographic security principles. The flaw allows attackers to perform man-in-the-middle attacks by presenting arbitrary X.509 certificates that appear legitimate to the vulnerable application, effectively undermining the entire purpose of SSL/TLS encryption.
This vulnerability specifically impacts the certificate validation process by bypassing the standard hostname checking mechanism that should ensure the server certificate's subject matches the domain name being accessed. The technical implementation flaw falls under the category of improper certificate validation, which is classified as CWE-295 in the Common Weakness Enumeration framework. The absence of proper hostname verification means that the application accepts any certificate that is otherwise valid, regardless of whether it corresponds to the intended PayPal domain. This weakness creates a pathway for attackers to intercept sensitive data transmission between the mobile application and PayPal's servers.
The operational impact of this vulnerability extends beyond simple data interception, as it enables attackers to manipulate financial transactions and access user account information. Mobile banking and payment applications are particularly vulnerable to such attacks due to the sensitive nature of the data they handle and the trust users place in the security of these applications. The vulnerability affects the confidentiality and integrity of data transmitted between the iOS device and PayPal's web services, potentially allowing attackers to capture login credentials, transaction details, and personal financial information. This weakness directly maps to ATT&CK technique T1041, which describes data compression and encryption for exfiltration, as well as T1566, which covers credential access through phishing and man-in-the-middle attacks.
Mitigation strategies for this vulnerability require immediate application updates to implement proper SSL/TLS certificate validation procedures. The fix should include enabling hostname verification during SSL/TLS handshakes and ensuring that the server certificate's subject alternative name or common name matches the target domain exactly. Security professionals should also implement certificate pinning mechanisms where possible, though this approach requires careful consideration of certificate lifecycle management and application updates. Organizations should conduct regular security assessments of mobile applications to identify similar certificate validation weaknesses and ensure compliance with industry standards such as NIST SP 800-57 for cryptographic key management and TLS protocol implementation. The vulnerability demonstrates the critical importance of proper SSL/TLS implementation in mobile applications and highlights the need for comprehensive security testing throughout the software development lifecycle to prevent similar issues in future releases.