CVE-2023-49208Network attack vector

Memory corruption via unchecked WebAuthn coordinate copies

Published Nov 23, 2023 · Updated Jun 5, 2025

Buffer overflow in Glewlwyd SSO server before 2.7.6 allows remote attackers to corrupt memory during FIDO2 credential registration. The register_new_attestation function copies credential-supplied CBOR COSE x and y byte strings into fixed 256-byte cert_x and cert_y buffers without first checking their lengths. Unauthenticated network access to the registration flow is sufficient; the documented consequence is memory corruption in the server process.

CVSS severity9.8
Critical
EPSS probability0.88%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Buffer overflow in Glewlwyd SSO server before 2.7.6 allows remote attackers to corrupt memory during FIDO2 credential registration. The register_new_attestation function copies credential-supplied CBOR COSE x and y byte strings into fixed 256-byte cert_x and cert_y buffers without first checking their lengths. Unauthenticated network access to the registration flow is sufficient; the documented consequence is memory corruption in the server process.

The record

CVE
CVE-2023-49208
Published
Nov 23, 2023
Updated
Jun 5, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-120, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Nov 23, 2023CVE publishedPublication date reported by the CVE source.
  2. Jun 5, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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