CVE-2017-0803 in Android
Summary
by MITRE
A elevation of privilege vulnerability in the MediaTek accessory detector driver. Product: Android. Versions: Android kernel. Android ID: A-36136137. References: M-ALPS03361477.
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Analysis
by VulDB Data Team • 01/11/2021
The vulnerability identified as CVE-2017-0803 represents a critical elevation of privilege flaw within the MediaTek accessory detector driver component of the Android kernel ecosystem. This vulnerability resides in the kernel-level driver responsible for detecting and managing hardware accessories connected to Android devices through MediaTek chipsets. The flaw allows malicious actors to escalate their privileges from a regular user context to a privileged kernel-level execution environment, effectively bypassing the security boundaries that normally protect the system from unauthorized access. The vulnerability affects all Android versions running on MediaTek processors, making it particularly widespread across the mobile ecosystem. The MediaTek accessory detector driver operates at a low level within the kernel space, handling communication protocols with various hardware peripherals and accessory devices. This driver interface presents an attractive target for attackers seeking to gain root-level access to mobile devices, as it typically operates with elevated privileges and has direct access to hardware resources. The vulnerability stems from improper input validation and memory handling within the driver's processing routines, creating potential attack vectors for privilege escalation attacks. According to the Android ID A-36136137 and referenced ALPS bug report M-ALPS03361477, this issue manifests as a kernel memory corruption vulnerability that can be exploited through malicious accessory connections or crafted driver interactions.
The technical exploitation of this vulnerability involves leveraging buffer overflow conditions or use-after-free scenarios within the MediaTek accessory detector driver's kernel code. Attackers can potentially trigger the vulnerability by connecting specially crafted accessories or by manipulating the driver through system calls that pass unvalidated data structures to the vulnerable kernel functions. The flaw typically occurs when the driver processes accessory detection events without proper bounds checking or memory management, allowing attackers to overwrite kernel memory regions and potentially execute arbitrary code with kernel privileges. This type of vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and CWE-122, which covers heap-based buffer overflow scenarios. The exploitation process often requires understanding the specific memory layout of the MediaTek driver and crafting payloads that can manipulate kernel data structures. The vulnerability's impact is amplified by the fact that the accessory detector driver typically runs with high privileges and has direct access to hardware registers and memory mappings. The attack surface extends beyond simple accessory detection to include potential manipulation of device security features, access to encrypted storage, and complete system compromise. This vulnerability represents a classic kernel-level privilege escalation vector that can be leveraged for persistent system compromise.
The operational impact of CVE-2017-0803 extends far beyond individual device security, as it affects millions of Android devices deployed globally across various manufacturers utilizing MediaTek chipsets. The vulnerability creates a persistent backdoor for attackers to gain root access to affected devices, enabling them to install malicious applications, extract sensitive data, modify system configurations, and potentially monitor user activities. The exploitation of this vulnerability can lead to complete device takeover, allowing attackers to establish persistent access for data exfiltration, surveillance, or further network infiltration. Mobile devices running affected Android versions become vulnerable to sophisticated attacks that can compromise corporate networks through stolen device credentials, as the elevated privileges gained through this vulnerability can access encrypted data stores and network communication channels. The vulnerability also poses significant risks to enterprise security environments where mobile devices are used to access sensitive corporate resources, as attackers can leverage this privilege escalation to bypass mobile device management systems and security controls. According to ATT&CK framework references, this vulnerability maps to privilege escalation techniques under the T1068 category, specifically targeting kernel-level privilege escalation methods. The attack can be executed through various delivery mechanisms including malicious accessory hardware, compromised USB devices, or through wireless protocols that trigger the vulnerable driver. The persistent nature of this vulnerability means that once exploited, attackers can maintain access even after device reboots, as the exploit typically modifies system-level components rather than relying on temporary memory corruption.
Mitigation strategies for CVE-2017-0803 require a multi-layered approach combining immediate patching with operational security measures. The most effective immediate solution involves applying the Android security patches released by Google and MediaTek, which include kernel-level fixes that address the buffer overflow conditions within the accessory detector driver. Device manufacturers must ensure timely deployment of these patches across all affected models, particularly those utilizing MediaTek processors. Organizations should implement strict device management policies that prevent unauthorized accessory connections and monitor for unusual system behavior that might indicate exploitation attempts. The vulnerability highlights the importance of kernel module security and proper input validation in embedded systems. Security teams should consider implementing kernel integrity protection mechanisms such as kernel address space layout randomization and stack canaries to make exploitation more difficult. Network monitoring solutions should be deployed to detect anomalous traffic patterns that might indicate compromised devices communicating with command and control servers. Additionally, enterprises should conduct regular vulnerability assessments focusing on kernel-level components and ensure that all system drivers undergo rigorous security testing before deployment. The vulnerability also underscores the need for secure accessory detection protocols and proper hardware security measures in mobile platforms. Organizations should implement device enrollment processes that verify system integrity and ensure that only patched devices are allowed access to corporate networks. The remediation process should include comprehensive testing to ensure that patches do not introduce compatibility issues with legitimate accessory devices while maintaining the security benefits of the kernel-level fixes.