ARM mbed TLS before 1.3.22, before 2.1.10, and before 2.7.0, when the truncated HMAC extension and CBC are used, allows remote attackers to execute arbitrary code or cause a denial of service (heap corruption) via a crafted application packet within a TLS or DTLS session.
ARM mbed TLS before 1.3.21 and 2.x before 2.1.9, if optional authentication is configured, allows remote attackers to bypass peer authentication via an X.509 certificate chain with many intermediates. NOTE: although mbed TLS was formerly known as PolarSSL, the releases shipped with the PolarSSL name are not affected.
An exploitable free of a stack pointer vulnerability exists in the x509 certificate parsing code of ARM mbed TLS before 1.3.19, 2.x before 2.1.7, and 2.4.x before 2.4.2. A specially crafted x509 certificate, when parsed by mbed TLS library, can cause an invalid free of a stack pointer leading to a potential remote code execution. In order to exploit this vulnerability, an attacker can act as either a client or a server on a network to deliver malicious x509 certificates to vulnerable applications.