CVE-2016-3897 in Android
Summary
by MITRE
The WifiEnterpriseConfig class in net/wifi/WifiEnterpriseConfig.java in Wi-Fi in Android 4.x before 4.4.4, 5.0.x before 5.0.2, 5.1.x before 5.1.1, and 6.x before 2016-09-01 includes a password in the return value of a toString method call, which allows attackers to obtain sensitive information via a crafted application, aka internal bug 25624963.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 09/15/2022
The vulnerability described in CVE-2016-3897 represents a critical information disclosure flaw within Android's Wi-Fi enterprise configuration system. This issue affects multiple Android versions including 4.x before 4.4.4, 5.0.x before 5.0.2, 5.1.x before 5.1.1, and 6.x before the specified date. The vulnerability stems from the WifiEnterpriseConfig class implementation in the net/wifi/WifiEnterpriseConfig.java file, where sensitive authentication credentials are inadvertently exposed through the toString method's return value. This flaw creates a direct pathway for malicious applications to extract Wi-Fi enterprise passwords, potentially compromising network security and user privacy. The vulnerability is particularly concerning as it exists within the core Wi-Fi management functionality of the operating system, making it accessible to any application with appropriate permissions.
The technical implementation of this vulnerability involves the improper handling of sensitive data within the toString method of the WifiEnterpriseConfig class. When the toString method is invoked, it returns a string representation of the configuration object that includes the password field in plaintext format. This behavior violates fundamental security principles of information hiding and sensitive data protection. The flaw is classified under CWE-209, Information Exposure Through an Error Message, and more specifically aligns with CWE-312, Cleartext Storage of Sensitive Information, as it exposes sensitive credentials through the application's output mechanism. The vulnerability demonstrates poor secure coding practices where authentication credentials are not properly sanitized or masked before being included in string representations that can be accessed by other applications.
The operational impact of CVE-2016-3897 extends beyond simple information disclosure, creating potential attack vectors for privilege escalation and network compromise. An attacker with a crafted malicious application can exploit this vulnerability to extract Wi-Fi enterprise passwords, which could then be used to gain unauthorized access to protected corporate networks. This exposure enables attackers to perform man-in-the-middle attacks, eavesdrop on network communications, and potentially escalate privileges within enterprise environments. The vulnerability also aligns with ATT&CK technique T1566, Phishing, as attackers could create deceptive applications that appear legitimate while harvesting credentials. The impact is particularly severe in enterprise environments where Wi-Fi enterprise authentication typically uses strong credentials such as EAP-TLS, EAP-PEAP, or EAP-TTLS protocols, making the exposed passwords highly valuable for unauthorized network access.
Mitigation strategies for CVE-2016-3897 require immediate patching of affected Android versions to ensure the secure handling of sensitive configuration data. Organizations should implement comprehensive network monitoring to detect unauthorized access attempts following the vulnerability disclosure. The Android security team addressed this issue through patches that modified the toString method implementation to exclude sensitive credential information from the returned string output. System administrators should conduct thorough vulnerability assessments to identify any applications that might be leveraging this vulnerability, while also implementing proper application permission controls to limit access to Wi-Fi configuration APIs. Additionally, organizations should consider implementing network segmentation and enhanced authentication mechanisms as compensating controls. The vulnerability highlights the importance of secure coding practices and proper input/output handling in mobile operating systems, emphasizing the need for regular security audits and code reviews to prevent similar information disclosure flaws in future implementations.