RFID Tear Off Attack: Bypassing Monotonic Counter Protection on NXP MIFARE Ultralight and NTAG Cards

CVE-2021-33881 · MEDIUM Severity

CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N

On NXP MIFARE Ultralight and NTAG cards, an attacker can interrupt a write operation (aka conduct a "tear off" attack) over RFID to bypass a Monotonic Counter protection mechanism. The impact depends on how the anti tear-off feature is used in specific applications such as public transportation, physical access control, etc.

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