scheme/webauthn.c in Glewlwyd SSO server through 2.5.3 has a buffer overflow during FIDO2…
Priority MEDIUM 45CWE-120Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-120 and the CVSS impact.
Summary
scheme/webauthn.c in Glewlwyd SSO server through 2.5.3 has a buffer overflow during FIDO2 signature validation in webauthn registration.
Why it matters now
EPSS 0.01492 74th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | — | all versions | — | No fix listed | CNA |
- — Vendor— Affected all versions Fixed in — No fix listed CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:glewlwyd_sso_server_project:glewlwyd_sso_server:*:*:*:*:*:*:*:* | up to 2.5.3 | Vulnerable | Glewlwyd Sso Server Project |
- cpe:2.3:a:glewlwyd_sso_server_project:glewlwyd_sso_server:*:*:*:*:*:*:*:* Versions up to 2.5.3 Vulnerable ·Glewlwyd Sso Server Project
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2021-40818
- 2026-10-03 Alias added: GHSA-ppv3-px64-q9mx
References
More Glewlwyd Sso Server Project Glewlwyd Sso Server vulnerabilities
- TI-2023-26859 scheme/webauthn.c in Glewlwyd SSO server before 2.7.6 has a possible buffer overflow… CVSS 3.1CRITICAL 9.8
- TI-2022-10359 scheme/webauthn.c in Glewlwyd SSO server 2.x before 2.6.2 has a buffer overflow associated with a webauthn assertion. CVSS 3.1CRITICAL 9.8
- TI-2024-16921 Glewlwyd SSO server 2.x through 2.7.6 allows open redirection via redirect_uri. CVSS 3.1MEDIUM 6.1
Sources
- CVE-2021-40818 · CVE Program
- CVE-2021-40818 · NVD
- FIRST EPSS
- GHSA-ppv3-px64-q9mx · GitHub Advisory Database · CC BY 4.0
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