CVE-2019-2134 in Android
Summary
by MITRE
In phFriNfc_ExtnsTransceive of phNxpExtns_MifareStd.cpp, there is a possible out of bounds write due to an integer overflow. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is needed for exploitation. Product: Android. Versions: Android-7.0 Android-7.1.1 Android-7.1.2 Android-8.0 Android-8.1 Android-9. Android ID: A-132083376.
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Analysis
by VulDB Data Team • 08/01/2020
The vulnerability identified as CVE-2019-2134 resides within the NFC (Near Field Communication) subsystem of Android operating systems, specifically in the phNxpExtns_MifareStd.cpp source file. This flaw manifests in the phFriNfc_ExtnsTransceive function where an integer overflow condition creates a potential out-of-bounds write scenario. The vulnerability affects multiple Android versions including 7.0, 7.1.1, 7.1.2, 8.0, 8.1, and 9.0, indicating a widespread impact across the Android ecosystem. The integer overflow occurs during NFC transaction processing when handling Mifare standard communication protocols, creating a scenario where malicious input could cause memory corruption beyond intended boundaries.
The technical nature of this vulnerability places it under CWE-190, which specifically addresses integer overflow conditions that can lead to memory corruption and arbitrary code execution. The flaw represents a classic buffer overflow vulnerability where an attacker can manipulate input parameters to cause an integer to wrap around to a small value, subsequently leading to an out-of-bounds write operation. This type of vulnerability falls within the ATT&CK framework under T1068, which covers 'Exploitation for Privilege Escalation' and T1059, 'Command and Scripting Interpreter', as it requires exploitation through NFC communication to achieve privilege escalation. The vulnerability's classification as a local privilege escalation means that an attacker with physical access to a device or the ability to establish NFC communication can potentially gain elevated system privileges.
The operational impact of CVE-2019-2134 extends beyond simple memory corruption as it enables local privilege escalation without requiring additional execution privileges, making it particularly dangerous in mobile environments where NFC is commonly used for transactions, device pairing, and data exchange. The requirement for user interaction suggests that exploitation typically occurs through NFC communication initiated by the victim, such as when tapping a device against another NFC-enabled device or when NFC transactions are automatically triggered by system processes. This attack vector aligns with the ATT&CK technique T1550.001, 'Use Alternate Authentication Material', as the vulnerability exploits NFC communication channels to establish a foothold for privilege escalation. The vulnerability's potential for exploitation in real-world scenarios is heightened by the widespread adoption of NFC technology in smartphones and the common use of NFC for mobile payments and device pairing.
Mitigation strategies for CVE-2019-2134 should focus on both immediate patching and architectural improvements to prevent similar vulnerabilities. Android security updates released in response to this vulnerability addressed the integer overflow condition by implementing proper input validation and bounds checking in the NFC transaction handling code. Organizations should prioritize applying the relevant Android security patches as soon as possible, particularly for devices that handle sensitive data or operate in high-security environments. The mitigation approach should include monitoring for unusual NFC activity patterns and implementing NFC communication restrictions where possible. Security practitioners should also consider network segmentation and device hardening measures to reduce the attack surface, particularly in enterprise environments where NFC-enabled devices may be used for sensitive transactions or access control. The vulnerability serves as a reminder of the importance of secure coding practices, particularly in embedded systems and mobile platforms where memory safety and input validation are critical for preventing privilege escalation attacks.