CVE-2021-33881

Severity Score

4.2

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

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.

En las tarjetas NXP MIFARE Ultralight y NTAG, un atacante puede interrumpir una operación de escritura (también se conoce como ataque "tear off") mediante RFID para omitir el mecanismo de protección Monotonic Counter. El impacto depende de cómo es usado la funcionalidad anti tear-off en aplicaciones específicas como el transporte público, el control de acceso físico, etc

*Credits: N/A

Attack Vector

Physical

Attack Complexity

High

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

High

Availability

None

Attack Vector

Local

Attack Complexity

Medium

Authentication

None

Confidentiality

None

Integrity

Partial

Availability

None

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2021-06-06 CVE Reserved
2021-06-06 CVE Published
2024-02-20 EPSS Updated
2024-08-04 CVE Updated
2024-08-04 First Exploit
---------- Exploited in Wild
---------- KEV Due Date

CWE

CWE-863: Incorrect Authorization

CAPEC

References (4)

URL	Tag	Source
https://blog.quarkslab.com/rfid-monotonic-counter-anti-tearing-defeated.html	Mitigation

URL	Date	SRC
https://www.sstic.org/2021/presentation/eeprom_it_will_all_end_in_tears	2024-08-04

URL	Date	SRC

URL	Date	SRC
https://www.nxp.com/docs/en/application-note/AN11340.pdf	2021-06-17
https://www.nxp.com/docs/en/application-note/AN13089.pdf	2021-06-17

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Nxp Search vendor "Nxp"	Mifare Ultralight Ev1 Firmware Search vendor "Nxp" for product "Mifare Ultralight Ev1 Firmware"	-	-	Affected	in	Nxp Search vendor "Nxp"	Mifare Ultralight Ev1 Search vendor "Nxp" for product "Mifare Ultralight Ev1"	-	-	Safe
Nxp Search vendor "Nxp"	Mifare Ultralight C Firmware Search vendor "Nxp" for product "Mifare Ultralight C Firmware"	-	-	Affected	in	Nxp Search vendor "Nxp"	Mifare Ultralight C Search vendor "Nxp" for product "Mifare Ultralight C"	-	-	Safe
Nxp Search vendor "Nxp"	Mifare Ultralight Nano Firmware Search vendor "Nxp" for product "Mifare Ultralight Nano Firmware"	-	-	Affected	in	Nxp Search vendor "Nxp"	Mifare Ultralight Nano Search vendor "Nxp" for product "Mifare Ultralight Nano"	-	-	Safe
Nxp Search vendor "Nxp"	Ntag 210 Firmware Search vendor "Nxp" for product "Ntag 210 Firmware"	-	-	Affected	in	Nxp Search vendor "Nxp"	Ntag 210 Search vendor "Nxp" for product "Ntag 210"	-	-	Safe
Nxp Search vendor "Nxp"	Ntag 212 Firmware Search vendor "Nxp" for product "Ntag 212 Firmware"	-	-	Affected	in	Nxp Search vendor "Nxp"	Ntag 212 Search vendor "Nxp" for product "Ntag 212"	-	-	Safe
Nxp Search vendor "Nxp"	Ntag 213 Firmware Search vendor "Nxp" for product "Ntag 213 Firmware"	-	-	Affected	in	Nxp Search vendor "Nxp"	Ntag 213 Search vendor "Nxp" for product "Ntag 213"	-	-	Safe
Nxp Search vendor "Nxp"	Ntag 215 Firmware Search vendor "Nxp" for product "Ntag 215 Firmware"	-	-	Affected	in	Nxp Search vendor "Nxp"	Ntag 215 Search vendor "Nxp" for product "Ntag 215"	-	-	Safe
Nxp Search vendor "Nxp"	Ntag 216 Firmware Search vendor "Nxp" for product "Ntag 216 Firmware"	-	-	Affected	in	Nxp Search vendor "Nxp"	Ntag 216 Search vendor "Nxp" for product "Ntag 216"	-	-	Safe