CVE-2014-9875 in Android
Summary
by MITRE
drivers/char/diag/diag_dci.c in the Qualcomm components in Android before 2016-08-05 on Nexus 7 (2013) devices allows attackers to gain privileges via a crafted application that sends short DCI request packets, aka Android internal bug 28767589 and Qualcomm internal bug CR483310.
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Analysis
by VulDB Data Team • 09/12/2022
The vulnerability identified as CVE-2014-9875 represents a critical privilege escalation flaw within the Qualcomm components of Android operating systems, specifically affecting Nexus 7 (2013) devices released prior to August 5, 2016. This issue resides in the diag_dci.c driver file which handles diagnostic communication interface operations, making it a fundamental component in the Android kernel's communication stack. The vulnerability stems from improper input validation and memory handling within the DCI request processing mechanism, creating a pathway for malicious applications to elevate their privileges and gain unauthorized access to system-level functionality.
The technical exploitation of this vulnerability occurs through the manipulation of DCI request packets, specifically targeting the handling of short or malformed packets within the diagnostic communication interface. Attackers can craft specially designed applications that send intentionally truncated DCI requests to the vulnerable driver, which fails to properly validate the packet length and structure before processing. This flaw allows for memory corruption and arbitrary code execution within the kernel context, as the driver does not adequately check the integrity of incoming requests before attempting to parse them. The vulnerability directly maps to CWE-129, which describes improper validation of array indices, and CWE-787, concerning out-of-bounds write operations. The root cause lies in the lack of proper bounds checking and input sanitization within the kernel driver's packet processing logic, creating a classic buffer overflow scenario that can be exploited to execute malicious code with kernel-level privileges.
The operational impact of this vulnerability is severe and far-reaching, as it enables attackers to bypass Android's security model entirely and gain root access to affected devices. Once exploited, the malicious application can perform any operation within the system, including modifying system files, accessing sensitive user data, installing additional malware, and completely compromising the device's security posture. The vulnerability affects a specific hardware platform - the Nexus 7 (2013) - but represents a broader class of issues affecting Qualcomm's diagnostic communication interfaces across multiple Android devices. The exploitation requires only a crafted application, making it particularly dangerous as it can be delivered through standard app distribution channels without requiring physical access or advanced technical skills from the attacker. This vulnerability aligns with ATT&CK technique T1068, which describes the use of privilege escalation techniques to gain system-level access, and T1059, covering the execution of malicious code through legitimate system interfaces.
Mitigation strategies for this vulnerability involve immediate patching of affected Android versions through security updates, as the fix requires modifications to the kernel driver's packet validation logic. System administrators and device manufacturers should prioritize applying the relevant security patches released by Google and Qualcomm to address the improper input validation in the diag_dci.c driver. Additionally, users should avoid installing untrusted applications and ensure their devices receive regular security updates. The vulnerability highlights the importance of proper input validation in kernel-level components and demonstrates the critical need for robust security testing of system drivers, particularly those handling privileged communication interfaces. Organizations should implement security monitoring to detect potential exploitation attempts and maintain up-to-date threat intelligence regarding similar vulnerabilities in Qualcomm's diagnostic components. The fix typically involves implementing proper bounds checking for incoming DCI request packets and ensuring that all packet lengths are validated before processing, preventing the memory corruption that enables privilege escalation.