– Update to 2.4.2
– CVE-2017-2784

Release notes: https://tls.mbed.org/tech-updates/releases/mbedtls-2.4.2-2.1.7-and-1.3.19-released
Security notes: https://tls.mbed.org/tech-updates/security-advisories/mbedtls-security-advisory-2017-01