CVE-2021-31924

Yubico pam-u2f before 1.1.1 has a logic issue that, depending on the pam-u2f configuration and the application used, could lead to a local PIN bypass. This issue does not allow user presence (touch) or cryptographic signature verification to be bypassed, so an attacker would still need to physically possess and interact with the YubiKey or another enrolled authenticator. If pam-u2f is configured to require PIN authentication, and the application using pam-u2f allows the user to submit NULL as the PIN, pam-u2f will attempt to perform a FIDO2 authentication without PIN. If this authentication is successful, the PIN requirement is bypassed.

CVSS v3.0 6.8 MEDIUM
CVSS v2.0 4.6 MEDIUM

6.8^/10

CVSS v3.0 : MEDIUM

Vector :

Exploitability : 0.9 / Impact : 5.9

Attack Vector PHYSICAL

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

4.6^/10

CVSS v2.0 : MEDIUM

Vector : AV:L/AC:L/Au:N/C:P/I:P/A:P

Exploitability : 3.9 / Impact : 6.4

Access Vector LOCAL

Access Complexity LOW

Authentication NONE

Confidentiality Impact PARTIAL

Integrity Impact PARTIAL

Availability Impact PARTIAL

References

Link	Resource
https://www.yubico.com/support/security-advisories/ysa-2021-03	Vendor Advisory
https://developers.yubico.com/pam-u2f/	Product Vendor Advisory
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/CRBVOZEMVO72FV4Z5O4GBGSURXHWRGD3/	Mailing List Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/IL3I5AKECLMK4ADLLACLOEF7H5CMNDP2/	Mailing List Third Party Advisory
https://security.gentoo.org/glsa/202208-11	Third Party Advisory

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Configurations

Configuration 1 (hide)

cpe:2.3:a:yubico:pam-u2f:*:*:*:*:*:*:*:*

Configuration 2 (hide)

OR	cpe:2.3:o:fedoraproject:fedora:34:::::::*
	cpe:2.3:o:fedoraproject:fedora:35:::::::*

Information

Published : 2021-05-25 17:15

Updated : 2022-12-09 10:17

NVD link : CVE-2021-31924

Mitre link : CVE-2021-31924

JSON object : View

CWE

CWE-287

Improper Authentication

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Products Affected

yubico

pam-u2f

fedoraproject

fedora

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