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)
02 Description
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)
03 Exploitation and scoring
- Exploitation
- Not assessed. CISA has not published an exploitation assessment for this record, and it is not in the KEV catalog. That is an absence of assessment, not a finding of no risk.
- SSVC decision
- Not assessed by CISA
- EPSS probability
- 0.33% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 26.3% of scored records. A rank, not a probability.
- NVD base score
- 6.8 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- NVD analysis status
- Modified. NVD last modified this record on 2026-06-17.
- Red Hat severity
- No Red Hat rating. Red Hat rates the CVEs that affect its products.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2021-05-25 23:40Z5 YR AGO
- Last updated
- 2024-08-03 23:10Z2 YR AGO
- Reserved
- 2021-04-30
- Assigning CNA
- mitre
- Record state
- PUBLISHED
- Severity
- Not rated by the issuing CNA
- CNA CVSS vector
- Not published by the issuing CNA
- Weaknesses
- CWE-287Improper AuthenticationClass
- Data version
- 5.1
- Document digest
- 75fca50588952517a9b0c379ef091e1d0d7da39cec8077fe699912b5a185076d
05 Affected products
06 References
- www.yubico.comhttps://www.yubico.com/support/security-advisories/ysa-2021-03
- developers.yubico.comhttps://developers.yubico.com/pam-u2f/
- lists.fedoraproject.orgFEDORA-2021-a52d48b1c2https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CRBVOZEMVO72FV4Z5O4GBGSURXHWRGD3/
- lists.fedoraproject.orgFEDORA-2021-724f4733e9https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IL3I5AKECLMK4ADLLACLOEF7H5CMNDP2/
- security.gentoo.orgGLSA-202208-11https://security.gentoo.org/glsa/202208-11
07 Fixed in
Arch Linux
- pam-u2f Fixed in 1.1.1-1
Source: Arch Linux Security Tracker, the Arch Linux security team. Reformatted by exploit.cc.
Debian 12
- pam-u2f Fixed in 1.1.0-1.1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 13
- pam-u2f Fixed in 1.1.0-1.1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
Debian 14
- pam-u2f Fixed in 1.1.0-1.1
Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.
A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.