CVE-2024-45159: trustedfirmware mbed_tls Improper Certificate Validation
Vulnerability summary
CVE-2024-45159 is a critical (CVSS 9.8) Improper Certificate Validation vulnerability in trustedfirmware mbed_tls. EPSS estimates a 0.39% chance of exploitation in the next 30 days, higher than 31.6% of scored vulnerabilities.
Timeline
- 05-09-2024PublishedVulnerability first disclosed.
- 13-03-2025Last modifiedVulnerability information updated.
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).
CVSS metrics
4 scores · 4 sources · 1 version- OSV · AlpineEcosystem advisory · calculated9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- OSV · UbuntuEcosystem advisory · calculated9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- NVDNIST9.8CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS trend
Probability
0.39%
Chance of exploitation in the next 30 days
Percentile
32%
Versus all other CVEs
30-day change
0.00 pp
From 0.39% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Alpine1 product
- mbedtls< 3.6.1-r0
Trustedfirmware1 product
- mbed_tls≥ 3.2.0, < 3.6.1
Ubuntu1 product
- mbedtlsAll versions (No fix recorded)
3 vendors · 3 products