CVE-2019-9358 in Android
Summary
by MITRE
In NFC, there is a possible out of bounds write due to a missing bounds check. This could lead to a to local escalation of privilege with no additional execution privileges needed. User interaction is needed for exploitation. Product: AndroidVersions: Android-10Android ID: A-120156401
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Analysis
by VulDB Data Team • 09/13/2020
The vulnerability identified as CVE-2019-9358 resides within the Near Field Communication (NFC) subsystem of Android operating systems, specifically affecting Android 10 and earlier versions. This issue represents a critical security flaw that demonstrates the importance of proper input validation in system-level components. The vulnerability manifests as a missing bounds check within the NFC processing code, creating a potential out-of-bounds write condition that can be exploited by malicious actors. The flaw is particularly concerning because it enables local privilege escalation without requiring additional execution privileges, meaning that an attacker who has already gained access to a user account could leverage this vulnerability to elevate their privileges to system level. The exploitation requires user interaction, suggesting that the attack vector likely involves tricking a user into interacting with a malicious NFC tag or device that triggers the vulnerable code path.
The technical nature of this vulnerability aligns with CWE-129, which describes improper validation of array index values, and more specifically relates to CWE-787, which covers out-of-bounds write conditions. The vulnerability operates at the kernel level within the NFC subsystem, where the system processes incoming NFC data without adequate bounds checking on buffer operations. When legitimate NFC data is processed, the system fails to validate the size or boundaries of incoming data structures, allowing an attacker to craft malicious NFC content that exceeds the allocated buffer space. This overflow condition can overwrite adjacent memory locations, potentially corrupting critical system data structures or executing arbitrary code. The out-of-bounds write vulnerability specifically targets memory management within the NFC service, where data from NFC tags or devices is parsed and processed before being handled by the system's security mechanisms. The attack surface is expanded by the fact that NFC is a commonly enabled feature on Android devices, making it a viable target for exploitation.
The operational impact of CVE-2019-9358 extends beyond simple privilege escalation, as it provides attackers with access to sensitive system resources and capabilities that could be used for further exploitation. Once elevated to system privileges, an attacker could access the device's secure storage, modify system files, install malicious applications, or even disable security features. The requirement for user interaction makes this vulnerability more challenging to exploit at scale, as it requires social engineering or physical proximity to the target device. However, the low barrier to entry for exploitation makes it particularly dangerous in targeted attacks, especially when combined with other vulnerabilities or when attackers have physical access to devices. The vulnerability affects all Android 10 devices and potentially earlier versions, creating a wide attack surface across multiple device manufacturers and models. The lack of additional execution privileges required for exploitation means that this vulnerability can be leveraged by attackers with minimal initial access, making it a preferred target for privilege escalation attacks.
Mitigation strategies for CVE-2019-9358 focus on both immediate patching and operational security measures. The primary solution involves applying the Android security patch released by Google, which includes proper bounds checking and input validation within the NFC subsystem. Organizations should implement comprehensive patch management procedures to ensure all Android devices are updated promptly, particularly in enterprise environments where device security is paramount. Additional mitigations include disabling NFC functionality when not actively needed, implementing network-based controls to monitor for suspicious NFC activity, and maintaining robust endpoint detection and response capabilities. The vulnerability also highlights the importance of secure coding practices and input validation in system-level components, aligning with ATT&CK technique T1068 which covers exploit for privilege escalation. Security teams should consider implementing device hardening measures that restrict NFC functionality to trusted applications and users, while also monitoring for unusual patterns in NFC data processing that might indicate exploitation attempts. Regular security assessments and penetration testing should include evaluation of NFC subsystems to identify similar vulnerabilities that might exist in other system components.