CVE-2019-9235 in Android
Summary
by MITRE
In NFC, there is a possible out of bounds read due to a missing bounds check. This could lead to local information disclosure with no additional execution privileges needed. User interaction is needed for exploitation. Product: AndroidVersions: Android-10Android ID: A-122323053
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Analysis
by VulDB Data Team • 09/12/2020
The vulnerability identified as CVE-2019-9235 resides within the Near Field Communication subsystem of Android operating systems, specifically affecting Android 10 and earlier versions. This issue represents a classic out-of-bounds read condition that occurs when the NFC component fails to properly validate array indices or buffer boundaries before accessing memory locations. The flaw manifests as a missing bounds check that allows unauthorized memory access patterns to occur during NFC data processing operations. Such vulnerabilities typically arise when developers assume that input data will conform to expected parameters without implementing proper validation mechanisms.
The technical implementation of this vulnerability places the NFC service in a precarious position where it processes untrusted data from external NFC devices or tags without adequate boundary validation. When the NFC subsystem receives malformed data structures or oversized payloads, the absence of proper bounds checking enables memory access beyond allocated buffer limits. This condition creates a potential information disclosure scenario where adjacent memory regions containing sensitive data may be inadvertently read and exposed. The vulnerability requires user interaction to exploit, meaning an attacker must convince a user to engage with a malicious NFC tag or device, typically through physical proximity or social engineering tactics.
From an operational perspective, this vulnerability represents a medium-severity risk that could lead to local information disclosure without requiring elevated privileges or root access. The attack vector necessitates physical proximity and user engagement, which limits its automated exploitation potential but does not eliminate the threat entirely. The information disclosure could potentially expose sensitive data such as cryptographic keys, user credentials, or system configuration details that might be stored in adjacent memory locations. Security researchers have classified this issue under CWE-129, which specifically addresses "Improper Validation of Array Index," while the attack pattern aligns with ATT&CK technique T1059.005 for command and scripting interpreter, though the actual exploitation would require specific NFC interaction methods.
The mitigation strategies for CVE-2019-9235 primarily focus on updating to patched Android versions where Google has implemented proper bounds checking mechanisms within the NFC subsystem. System administrators should ensure that all Android devices are updated to the latest security patches, particularly those addressing NFC-related vulnerabilities. Additional protective measures include implementing NFC device whitelisting policies, restricting NFC functionality in high-security environments, and monitoring for unusual NFC activity patterns. Organizations should also consider deploying network segmentation controls to limit potential information exposure and implement comprehensive monitoring solutions that can detect anomalous NFC data access patterns. The vulnerability demonstrates the critical importance of bounds checking in mobile operating systems, where NFC functionality must handle diverse and potentially malicious data inputs from various external sources.