The x509parse_crt function in x509.h in PolarSSL 1.1.x before 1.1.7 and 1.2.x before 1.2.8 does not properly parse certificate messages during the SSL/TLS handshake, which allows remote attackers to cause a denial of service (infinite loop and CPU consumption) via a certificate message that contains a PEM encoded certificate.
Improper Input Validation The product receives input or data, but it does
not validate or incorrectly validates that the input has the
properties that are required to process the data safely and
correctly.