CVE-2019-2133 in Android
Summary
by MITRE
In Mfc_Transceive of phNxpExtns_MifareStd.cpp, there is a possible out of bounds write due to a heap buffer 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-132082342.
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Analysis
by VulDB Data Team • 08/01/2020
The vulnerability identified as CVE-2019-2133 resides within the Mfc_Transceive function of the phNxpExtns_MifareStd.cpp file, which is part of the Android operating system's NFC (Near Field Communication) stack. This flaw represents a heap buffer overflow condition that occurs when processing NFC transactions involving Mifare standard cards. The vulnerability specifically affects Android versions 7.0 through 9.0, making it a significant concern for a wide range of mobile devices that utilize NFC functionality. The issue stems from inadequate bounds checking during the processing of data received from NFC card communications, creating a potential pathway for malicious actors to exploit memory corruption vulnerabilities.
The technical implementation of this vulnerability involves a classic heap buffer overflow scenario where the Mfc_Transceive function fails to properly validate the size of data being written to heap-allocated memory buffers. When NFC transactions occur with Mifare standard cards, the system processes data that may exceed the allocated buffer space, resulting in memory corruption that can overwrite adjacent memory locations. This type of vulnerability falls under CWE-121 Heap-based Buffer Overflow, which is classified as a critical security weakness in memory management. The flaw allows an attacker to write data beyond the boundaries of allocated memory regions, potentially corrupting other variables, function return addresses, or critical system structures.
The operational impact of this vulnerability extends beyond simple memory corruption, as it enables local privilege escalation without requiring additional execution privileges or user interaction beyond the initial NFC transaction. This means that an attacker with physical access to a vulnerable device could potentially exploit the vulnerability during normal NFC card reading operations, such as when using contactless payment systems, access control cards, or other NFC-enabled applications. The privilege escalation occurs because the vulnerable code executes with elevated privileges necessary for NFC operations, allowing the attacker to potentially gain root access to the device. This vulnerability aligns with ATT&CK technique T1068, which covers local privilege escalation through exploitation of system vulnerabilities, and specifically targets the Android operating system's NFC subsystem.
The exploitation of this vulnerability requires user interaction in the form of NFC card transactions, making it particularly dangerous in real-world scenarios where users frequently interact with NFC-enabled devices. Attackers could craft malicious NFC cards or manipulate NFC communication parameters to trigger the buffer overflow condition during legitimate NFC operations. The Android ID A-132082342 assigned to this vulnerability indicates its classification within Google's internal tracking system for Android security issues. This vulnerability demonstrates the critical importance of proper input validation and bounds checking in system-level code, particularly in components that handle external data inputs such as NFC communications. The vulnerability represents a significant risk to user privacy and device security, as successful exploitation could lead to complete device compromise and unauthorized access to sensitive user data stored on the device.