CVE-2019-2017 in Android
Summary
by MITRE
In rw_t2t_handle_tlv_detect_rsp of rw_t2t_ndef.cc, there is a possible out-of-bound write due to a missing bounds check. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is needed for exploitation.Product: AndroidVersions: Android-7.0 Android-7.1.1 Android-7.1.2 Android-8.0 Android-8.1 Android-9Android ID: A-121035711
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Analysis
by VulDB Data Team • 10/07/2023
The vulnerability identified as CVE-2019-2017 resides within the Near Field Communication (NFC) stack of Android operating systems, specifically in the rw_t2t_handle_tlv_detect_rsp function located in the rw_t2t_ndef.cc source file. This flaw represents a classic out-of-bounds write vulnerability that occurs when the system fails to properly validate input data before processing it. The issue manifests during NFC tag detection operations where the system attempts to handle Type-Length-Value (TLV) responses from NFC tags, creating a scenario where maliciously crafted NFC tag data could trigger memory corruption.
The technical root cause of this vulnerability stems from insufficient bounds checking within the NFC tag response handling mechanism. When the rw_t2t_handle_tlv_detect_rsp function processes incoming TLV data structures, it does not adequately validate the length parameters provided in the TLV header against the actual available buffer space. This missing validation allows an attacker to craft NFC tag responses that contain oversized data structures, causing the system to write data beyond the allocated memory boundaries. The vulnerability is classified as CWE-129 Input Validation and Output Processing, specifically representing an improper input validation scenario that leads to memory corruption.
The operational impact of this vulnerability extends beyond simple memory corruption, as it enables local privilege escalation without requiring any additional execution privileges or user interaction beyond the initial NFC tag detection. An attacker could potentially exploit this vulnerability by placing a malicious NFC tag in proximity to an affected Android device, allowing the system to automatically detect and process the tag during normal NFC operations. The privilege escalation occurs because the out-of-bounds write can overwrite critical system memory locations, potentially allowing an attacker to modify system processes or gain elevated privileges within the Android security sandbox. This represents a significant security risk as it can be exploited through passive NFC tag interactions without requiring user consent or explicit malicious actions.
Mitigation strategies for CVE-2019-2017 should focus on implementing proper bounds checking mechanisms within the NFC processing stack, ensuring that all TLV length parameters are validated against available buffer space before any data processing occurs. Android security updates addressing this vulnerability typically include patches that enforce strict bounds checking in the NFC tag response handling code, preventing oversized data structures from causing memory corruption. Organizations should prioritize applying the relevant Android security patches released by Google, as these updates specifically address the missing validation checks in the rw_t2t_ndef.cc file. Additionally, implementing NFC security policies that limit automatic tag detection and processing in sensitive environments can provide additional defense-in-depth measures. The vulnerability aligns with ATT&CK technique T1059 Command and Scripting Interpreter, as it enables privilege escalation through system-level memory corruption that can be leveraged to execute malicious code with elevated privileges.