CVE-2016-8480 in Android
Summary
by MITRE
An elevation of privilege vulnerability in the Qualcomm Secure Execution Environment Communicator driver could enable a local malicious application to execute arbitrary code within the context of the kernel. This issue is rated as High because it first requires compromising a privileged process. Product: Android. Versions: Kernel-3.10, Kernel-3.18. Android ID: A-31804432. References: QC-CR#1086186.
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Analysis
by VulDB Data Team • 11/12/2022
The vulnerability identified as CVE-2016-8480 represents a critical elevation of privilege flaw within the Qualcomm Secure Execution Environment Communicator driver component of Android systems. This vulnerability exists in kernel versions 3.10 and 3.18, making it particularly concerning as these versions were widely deployed across numerous mobile devices. The issue stems from insufficient input validation and improper privilege handling within the secure execution environment driver, which is responsible for facilitating communication between the trusted execution environment and the main operating system. The vulnerability is classified as High severity because it requires an initial compromise of a privileged process, but once achieved, it provides attackers with kernel-level execution capabilities that can be leveraged to gain complete system control.
The technical exploitation of this vulnerability occurs through a flaw in how the Qualcomm Secure Execution Environment Communicator driver handles certain communication protocols and data structures. When a malicious application successfully compromises a privileged process, it can manipulate the driver's behavior to execute arbitrary code within the kernel context. This flaw typically involves buffer overflow conditions or improper access control mechanisms that allow unprivileged code execution to transition into privileged kernel mode. The vulnerability specifically targets the communication channel between the secure element and the main system, where insufficient validation of input parameters enables attackers to craft malicious payloads that bypass normal privilege boundaries. This represents a classic example of a kernel-level privilege escalation vulnerability that can be categorized under CWE-20, which deals with improper input validation.
The operational impact of CVE-2016-8480 extends far beyond simple privilege escalation, as successful exploitation provides attackers with complete control over the device's kernel execution environment. This allows for persistent rootkit installation, complete data exfiltration, and the ability to modify or disable security mechanisms such as SELinux policies and encryption services. The vulnerability affects devices running Android versions that utilize the affected kernel versions, making it a widespread concern across the mobile ecosystem. Attackers can leverage this vulnerability to create backdoors that survive device reboots, modify system binaries, and access sensitive data stored in the secure execution environment. The implications are particularly severe given that the secure execution environment is designed to provide a trusted zone for sensitive operations such as cryptographic key storage and biometric authentication.
Mitigation strategies for CVE-2016-8480 primarily focus on timely patching and system updates from device manufacturers, as Qualcomm released security updates addressing this specific vulnerability. Organizations and users should prioritize applying the latest security patches provided by their device vendors, which typically include kernel updates and driver modifications that address the input validation flaws. Additionally, implementing application whitelisting and monitoring for suspicious kernel-level activities can help detect exploitation attempts. From a defensive perspective, this vulnerability aligns with ATT&CK technique T1068, which involves privilege escalation through local exploitation, and demonstrates the importance of maintaining secure kernel interfaces. Network administrators should also consider implementing device integrity monitoring solutions that can detect unauthorized modifications to kernel components, as the vulnerability's exploitation could result in persistent system compromise that may not be immediately apparent through standard security monitoring. The remediation process should include comprehensive testing of patches to ensure they do not introduce regressions in device functionality while effectively addressing the kernel privilege escalation vulnerability.