CVE-2021-31924
Published: 26 May 2021
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.
Priority
Status
| Package | Release | Status |
|---|---|---|
|
pam-u2f Launchpad, Ubuntu, Debian |
bionic |
Needs triage
|
| focal |
Needs triage
|
|
| groovy |
Ignored
(end of life)
|
|
| hirsute |
Ignored
(end of life)
|
|
| impish |
Ignored
(end of life)
|
|
| jammy |
Needs triage
|
|
| kinetic |
Ignored
(end of life, was needs-triage)
|
|
| lunar |
Ignored
(end of life, was needs-triage)
|
|
| mantic |
Needs triage
|
|
| trusty |
Does not exist
|
|
| upstream |
Needs triage
|
|
| xenial |
Needs triage
|
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 6.8 |
| Attack vector | Physical |
| Attack complexity | Low |
| Privileges required | None |
| User interaction | None |
| Scope | Unchanged |
| Confidentiality | High |
| Integrity impact | High |
| Availability impact | High |
| Vector | CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |