CVE-2016-2442 in Android
Summary
by MITRE
The Qualcomm buspm driver in Android before 2016-05-01 on Nexus 5X, 6, and 6P devices allows attackers to gain privileges via a crafted application, aka internal bug 26494907.
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Analysis
by VulDB Data Team • 11/07/2018
The vulnerability identified as CVE-2016-2442 represents a critical privilege escalation flaw within the Qualcomm buspm driver component of Android operating systems. This issue specifically affects Nexus 5X, 6, and 6P devices running Android versions prior to the 2016-05-01 security patch. The vulnerability stems from inadequate input validation and improper privilege handling within the kernel-level driver responsible for managing power management operations on these devices. Attackers can exploit this weakness by installing a malicious application that leverages the flawed driver to elevate their privileges from standard user level to system level access. The vulnerability is classified under CWE-20, which represents "Improper Input Validation," and falls within the broader category of kernel-level privilege escalation attacks that can be mapped to ATT&CK technique T1068, "Exploitation for Privilege Escalation."
The technical implementation of this vulnerability involves the Qualcomm buspm driver's failure to properly validate or sanitize input parameters passed to its kernel interfaces. When a crafted application interacts with the vulnerable driver through specific system calls or ioctl operations, it can manipulate the driver's behavior to execute arbitrary code with elevated privileges. This occurs because the driver lacks proper access controls and validation mechanisms that would normally prevent unauthorized privilege escalation attempts. The flaw allows attackers to bypass the standard Android security model by directly interacting with the power management subsystem at kernel level, where the driver operates with high privileges to manage device power states and hardware resources.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with complete system control over affected devices. Once successfully exploited, the malicious application can access all device resources, read sensitive user data, modify system configurations, install additional malware, and potentially disable security features. The vulnerability affects a significant number of devices since Nexus 5X, 6, and 6P were popular Android smartphones that received widespread adoption. The exploitation requires only a standard application installation, making it particularly dangerous as users may unknowingly grant permissions to malicious applications that could then leverage this vulnerability. This type of attack vector is especially concerning in mobile environments where users frequently download applications from various sources, including unofficial app stores or untrusted third-party sources.
Mitigation strategies for CVE-2016-2442 primarily focus on applying the official Android security patches released by Google and Qualcomm. Users should immediately update their devices to Android versions containing the fix for this vulnerability, which was included in the 2016-05-01 security update cycle. Device manufacturers should also implement proper kernel driver validation and privilege control mechanisms to prevent similar issues in future releases. Security researchers and organizations should monitor for any potential exploits targeting this vulnerability and maintain updated threat intelligence feeds. Additionally, users should exercise caution when installing applications, particularly from untrusted sources, as the vulnerability can be exploited through seemingly legitimate applications. The fix typically involves strengthening input validation within the buspm driver and implementing proper privilege checks to ensure that only authorized processes can access critical power management functions. This vulnerability highlights the importance of kernel-level security hardening and proper privilege separation in mobile operating systems, as it demonstrates how low-level driver flaws can compromise entire device security models.