synced 5 MIN AGO
01 Record

CVE-2021-40818

scheme/webauthn.c in Glewlwyd SSO server through 2.5.3 has a buffer overflow during FIDO2 signature validation in webauthn registration.

UnratedPUBLISHEDCNA: mitre
CNA base scoreUnratedNo CNA CVSS vector

02 Description

scheme/webauthn.c in Glewlwyd SSO server through 2.5.3 has a buffer overflow during FIDO2 signature validation in webauthn registration.

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
1.49% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 73.6% of scored records. A rank, not a probability.
NVD base score
9.8 (CVSS v3.x), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:3.1/AV:N/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
2021-09-08 21:47Z5 YR AGO
Last updated
2024-08-04 02:51Z2 YR AGO
Reserved
2021-09-08
Assigning CNA
mitre
Record state
PUBLISHED
Severity
Not rated by the issuing CNA
CNA CVSS vector
Not published by the issuing CNA
Weaknesses
  • CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')Base
Data version
5.1
Document digest
919c757f9b4f42080a1b5aae1d55fd887d533184b963a706011479c44218e17f

05 Affected products

VendorProductVersionsPlatforms
glewlwyd_sso_server_projectglewlwyd_sso_serverNot specified—

06 References

07 Fixed in

Debian 12

  • glewlwyd
    Fixed in 2.5.2-3

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 13

  • glewlwyd
    Fixed in 2.5.2-3

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 18.04 LTS

  • glewlwyd
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 20.04 LTS

  • glewlwyd
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 22.04 LTS

  • glewlwyd
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. 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.