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CVE-2024-45159

CRITICALCVSS 9.8/10EPSS 0.39%

Last modified

CVE-2024-45159 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. An issue was discovered in Mbed TLS 3.x before 3.6.1. With TLS 1.3, when a server enables optional authentication of the client, if the client-provided certificate does not have appropriate values in if keyUsage or extKeyUsage extensions, then the return value of mbedtls_ssl_get_verify_result() would incorrectly have the MBEDTLS_X509_BADCERT_KEY_USAGE and MBEDTLS_X509_BADCERT_KEY_USAGE bits clear. EPSS estimates a 0.39% chance of exploitation in the next 30 days.

Description

An issue was discovered in Mbed TLS 3.x before 3.6.1. With TLS 1.3, when a server enables optional authentication of the client, if the client-provided certificate does not have appropriate values in if keyUsage or extKeyUsage extensions, then the return value of mbedtls_ssl_get_verify_result() would incorrectly have the MBEDTLS_X509_BADCERT_KEY_USAGE and MBEDTLS_X509_BADCERT_KEY_USAGE bits clear. As a result, an attacker that had a certificate valid for uses other than TLS client authentication would nonetheless be able to use it for TLS client authentication. Only TLS 1.3 servers were affected, and only with optional authentication (with required authentication, the handshake would be aborted with a fatal alert).

Metrics

CVSS 3.1
9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability
0.39%

30.5th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
TrustedfirmwareMbed Tls>= 3.2.0, < 3.6.1

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2024-45159?
An issue was discovered in Mbed TLS 3.x before 3.6.1. With TLS 1.3, when a server enables optional authentication of the client, if the client-provided certificate does not have appropriate values in if keyUsage or extKeyUsage extensions, then the return value of mbedtls_ssl_get_verify_result() would incorrectly have the MBEDTLS_X509_BADCERT_KEY_USAGE and MBEDTLS_X509_BADCERT_KEY_USAGE bits clear. As a result, an attacker that had a certificate valid for uses other than TLS client authentication would nonetheless be able to use it for TLS client authentication. Only TLS 1.3 servers were affected, and only with optional authentication (with required authentication, the handshake would be aborted with a fatal alert).
How severe is CVE-2024-45159?
CVE-2024-45159 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 0.39% probability of exploitation in the next 30 days.
How do I fix CVE-2024-45159?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2024-45159?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST