CVE-2017-7978 in Phone
Summary
by MITRE
Samsung Android devices with L(5.0/5.1), M(6.0), and N(7.x) software allow attackers to obtain sensitive information by reading a world-readable log file after an unexpected reboot. The Samsung ID is SVE-2017-8290.
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Analysis
by VulDB Data Team • 11/07/2019
This vulnerability affects Samsung Android devices running versions lollipop 5.0 through 5.1 marshmallow 6.0 and nougat 7.x where an improper access control flaw exists in the system logging mechanism. The vulnerability stems from a world-readable log file that persists after unexpected device reboots, allowing unauthorized access to sensitive information. This represents a critical security oversight in the Android platform's permission model and file system access controls. The issue manifests when the system fails to properly clear or secure sensitive log data during unexpected shutdown scenarios, creating a persistent security exposure that remains accessible to any application or user with file system access.
The technical flaw resides in the Android system's handling of log files during unexpected reboots, specifically within the logging subsystem's access control implementation. When devices experience unexpected shutdowns or crashes, the system does not properly secure or clear sensitive information stored in log files that remain world-readable. This allows attackers to access sensitive data including but not limited to system logs, application data, and potentially personal information that should remain protected. The vulnerability is categorized under CWE-276 which specifically addresses improper file permissions and inadequate access control mechanisms. The flaw demonstrates a failure in the principle of least privilege where system resources should not be accessible to unauthorized entities.
The operational impact of this vulnerability is significant as it provides attackers with a persistent means of information gathering and potential data exfiltration. An attacker with local access to a compromised device can exploit this vulnerability to extract sensitive information without requiring elevated privileges or additional attack vectors. The vulnerability is particularly concerning because it persists across device reboots and does not require user interaction or specific conditions to be exploited. This creates a continuous threat vector that can be leveraged for reconnaissance, credential harvesting, or further attack escalation. The vulnerability also aligns with ATT&CK technique T1083 which covers the discovery of system information through file and directory listing capabilities.
Mitigation strategies should focus on immediate patch deployment through Samsung's security updates and Android system updates. Device administrators should implement proper access control policies and regularly audit system log files for unauthorized access. The vulnerability highlights the importance of proper secure boot processes and the need for robust file system access controls during system recovery scenarios. Organizations should also consider implementing additional monitoring and alerting mechanisms to detect unauthorized access to sensitive system files. The patch resolution should include enhanced access control mechanisms for log files and proper secure clearing procedures during unexpected shutdown events. Regular security assessments of system logging mechanisms should be conducted to identify similar access control flaws that could potentially be exploited in similar scenarios.