CVE-2024-45159Network attack vector

Client authentication bypass via omitted certificate-usage flags

Published Sep 5, 2024 · Updated Mar 13, 2025

Authentication bypass in Mbed TLS 3.2.0 through 3.6.0 allows remote attackers to access TLS 1.3 servers with an unsuitable certificate. The mbedtls_ssl_get_verify_result() function leaves the bad-key-usage result bits clear when keyUsage lacks digitalSignature or extKeyUsage lacks clientAuth. The server must enable TLS 1.3 optional client authentication, and the certificate must otherwise chain to a trusted CA; required authentication and TLS 1.2 are unaffected.

CVSS severity9.8
Critical
EPSS probability0.39%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in Mbed TLS 3.2.0 through 3.6.0 allows remote attackers to access TLS 1.3 servers with an unsuitable certificate. The mbedtls_ssl_get_verify_result() function leaves the bad-key-usage result bits clear when keyUsage lacks digitalSignature or extKeyUsage lacks clientAuth. The server must enable TLS 1.3 optional client authentication, and the certificate must otherwise chain to a trusted CA; required authentication and TLS 1.2 are unaffected.

The record

CVE
CVE-2024-45159
Published
Sep 5, 2024
Updated
Mar 13, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-295
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 5, 2024CVE publishedPublication date reported by the CVE source.
  2. Mar 13, 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

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-295Improper Certificate Validation

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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