CVE-2020-36477

Medium

Description

An issue was discovered in Mbed TLS before 2.24.0. The verification of X.509 certificates when matching the expected common name (the cn argument of mbedtls_x509_crt_verify) with the actual certificate name is mishandled: when the subjecAltName extension is present, the expected name is compared to any name in that extension regardless of its type. This means that an attacker could impersonate a 4-byte or 16-byte domain by getting a certificate for the corresponding IPv4 or IPv6 address (this would require the attacker to control that IP address, though).

SeverityMedium
CVSS5.9
Exploit probability—
ProductArm Mbed Tls
PublishedAug 23, 2021
First seenAug 23, 2021

How to fix

Update
  • arm mbed_tls2.24.0 or later

Affected products

ProductAffected versionsFixed in
arm mbed_tlsv < 2.24.02.24.0

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