CVE-2020-0143 in Android
Summary
by MITRE
In nfa_dm_ndef_find_next_handler of nfa_dm_ndef.c, there is a possible out of bounds read due to a missing bounds check. This could lead to local information disclosure of heap data via compromised device firmware with System execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-10Android ID: A-145597277
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Analysis
by VulDB Data Team • 06/12/2020
The vulnerability identified as CVE-2020-0143 resides within the nfa_dm_ndef_find_next_handler function of the nfa_dm_ndef.c file in Android's NFC (Near Field Communication) stack. This flaw represents a classic out-of-bounds read condition that occurs when the system fails to properly validate array indices before accessing memory locations. The issue is classified under CWE-129 as an insufficient bounds checking vulnerability, which directly enables unauthorized memory access patterns that can lead to information disclosure. The vulnerability exists in the NFC subsystem's Data Management component, specifically within the NDEF (NFC Data Exchange Format) handling logic where the system processes incoming NFC data structures.
The technical exploitation of this vulnerability requires an attacker with System execution privileges, typically achieved through compromised device firmware or a malicious application with elevated privileges. The out-of-bounds read occurs when the function processes NDEF records without adequate validation of the data boundaries, allowing an attacker to read adjacent heap memory locations that may contain sensitive information such as cryptographic keys, user credentials, or other confidential data. This type of information disclosure vulnerability is particularly dangerous in mobile environments where device firmware may contain proprietary data or authentication tokens. The ATT&CK framework categorizes this as a privilege escalation technique under T1068, where an attacker leverages existing system privileges to extract sensitive information from memory.
The operational impact of this vulnerability extends beyond simple information disclosure, as the compromised device firmware could provide attackers with access to critical system components that may facilitate further exploitation. When an attacker successfully triggers this vulnerability, they can potentially extract heap data that may include session tokens, encryption keys, or other sensitive information stored in adjacent memory locations. This information could then be used to impersonate users, decrypt communications, or gain deeper access to the device's secure elements. The vulnerability's exploitation does not require user interaction, making it particularly concerning for embedded systems and IoT devices where automatic processing of NFC data occurs. The Android security model considers this a medium to high severity issue given that it requires only system-level privileges to exploit, and the heap memory access pattern can reveal substantial amounts of sensitive data.
Mitigation strategies for CVE-2020-0143 should focus on implementing proper bounds checking within the NDEF processing functions and ensuring that all memory accesses are validated against array boundaries. Android vendors should apply patches that include additional input validation routines and heap memory integrity checks. The recommended approach involves adding comprehensive boundary validation before any memory access operations in the nfa_dm_ndef_find_next_handler function, ensuring that all indices are properly checked against the actual size of the data structures being processed. Additionally, implementing memory protection mechanisms such as stack canaries, address space layout randomization, and heap integrity checks can further reduce the exploitation surface. Device manufacturers should also consider implementing firmware update mechanisms that can automatically patch vulnerable systems without requiring user intervention, as the vulnerability's exploitation does not require user interaction and can occur during normal NFC operations. Regular security audits of NFC subsystems should include thorough reviews of memory access patterns to identify similar out-of-bounds conditions that could lead to information disclosure vulnerabilities.