CVE-2019-9238 in Android
Summary
by MITRE
In the NFC stack, there is a possible out of bounds write due to a missing bounds check. This could lead to local escalation of privilege with System execution privileges needed. User interaction is needed for exploitation. Product: AndroidVersions: Android-10Android ID: A-121267042
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Analysis
by VulDB Data Team • 09/12/2020
The vulnerability identified as CVE-2019-9238 resides within the NFC (Near Field Communication) stack of Android operating systems, specifically affecting Android 10 and earlier versions. This issue represents a critical security flaw that demonstrates the dangers of insufficient input validation in system-level components. The vulnerability manifests as a missing bounds check during NFC data processing, creating a potential out-of-bounds write condition that could be exploited by malicious actors. The Android ID A-121267042 categorizes this flaw within the broader context of system security vulnerabilities that require careful consideration of privilege escalation mechanisms.
The technical implementation of this vulnerability occurs within the NFC subsystem where data packets are processed and handled by the underlying system components. When NFC data is received and processed, the system fails to properly validate the boundaries of memory allocations, allowing an attacker to potentially write data beyond the allocated memory space. This missing bounds check creates a scenario where maliciously crafted NFC data could overwrite adjacent memory locations, potentially corrupting critical system structures or executing arbitrary code. The flaw operates at the system level, requiring system execution privileges for exploitation but offering a pathway for local privilege escalation that could be leveraged by attackers who have already gained some level of system access.
The operational impact of CVE-2019-9238 extends beyond simple data corruption, as it provides a potential pathway for attackers to escalate privileges within the Android environment. While the vulnerability requires user interaction for exploitation, this interaction can occur through NFC data transmission, making it particularly concerning in environments where NFC communications are frequent. The local privilege escalation capability means that an attacker who successfully exploits this vulnerability could gain system-level privileges, potentially enabling them to access sensitive data, modify system files, or even install malicious applications with elevated permissions. This vulnerability aligns with CWE-129, which describes improper validation of array index bounds, and represents a classic example of how memory safety issues can create significant security risks in mobile operating systems.
Mitigation strategies for this vulnerability should focus on both immediate patching and operational security measures. Android security updates addressing this issue should be deployed immediately across all affected devices, as the vulnerability represents a significant risk to system integrity and user data protection. Organizations should implement network monitoring to detect unusual NFC activity patterns that might indicate exploitation attempts, while also ensuring that NFC functionality is disabled when not required for business operations. The ATT&CK framework categorizes this type of vulnerability under privilege escalation techniques, specifically targeting system-level access through memory corruption flaws. Security teams should monitor for indicators of compromise related to NFC-based attacks and consider implementing application whitelisting policies to limit the potential impact of such exploits. Additionally, regular security assessments of NFC implementations should be conducted to identify similar vulnerabilities that may exist in other system components, as this type of memory safety issue is often replicated across different software modules and platforms.