CVE-2017-13272 in Android
Summary
by MITRE
In alarm_ready_generic of alarm.cc, there is a possible out of bounds write due to a use after free. This could lead to remote escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation. Product: Android. Versions: 7.0, 7.1.1, 7.1.2, 8.0, 8.1. Android ID: A-67110137.
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Analysis
by VulDB Data Team • 01/21/2020
The vulnerability identified as CVE-2017-13272 represents a critical use after free condition within the Android alarm system implementation, specifically affecting the alarm_ready_generic function in alarm.cc. This flaw exists in multiple Android versions including 7.0, 7.1.1, 7.1.2, 8.0, and 8.1, making it a widespread security concern that affects a significant portion of the Android ecosystem. The vulnerability is classified under CWE-416 as a use after free error, which occurs when a program continues to reference memory after it has been freed, potentially leading to unpredictable behavior and exploitation opportunities.
The technical implementation flaw stems from improper memory management within the alarm subsystem where a pointer reference is maintained after the associated memory block has been deallocated. When the alarm_ready_generic function processes alarm events, it fails to properly validate the state of memory references before performing write operations, creating an opportunity for attackers to manipulate the system's memory layout. This particular vulnerability is particularly dangerous because it can be exploited remotely without requiring any additional execution privileges or user interaction, making it a highly attractive target for malicious actors seeking to escalate their privileges within the Android environment.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it allows attackers to gain elevated system privileges through a remote attack vector that requires no user engagement. This characteristic places the vulnerability in the ATT&CK framework under privilege escalation techniques where adversaries can leverage system-level flaws to gain unauthorized access to sensitive system resources. The absence of user interaction requirements significantly increases the exploitability and potential for automated attacks, making it a severe concern for device security and user privacy.
Mitigation strategies for CVE-2017-13272 should prioritize immediate patch deployment from Android security updates, as the vulnerability exists in multiple versions of the operating system and affects the core alarm subsystem functionality. Organizations and users should ensure their Android devices are updated to versions that contain the patched alarm.cc implementation, which addresses the memory management issues in the alarm_ready_generic function. Additionally, network administrators should monitor for any exploitation attempts and consider implementing network segmentation to limit potential attack surfaces, while security teams should conduct thorough vulnerability assessments to identify any potential exploitation attempts within their environments. The vulnerability demonstrates the critical importance of proper memory management in system-level components and highlights the need for comprehensive security testing of core Android subsystems to prevent similar issues from emerging in the future.