The asn1_get_sequence_of function in library/asn1parse.c in PolarSSL 1.0 through 1.2.12 and 1.3.x through 1.3.9 does not properly initialize a pointer in the asn1_sequence linked list, which allows remote attackers to cause a denial of service (crash) or possibly execute arbitrary code via a crafted ASN.1 sequence in a certificate.

The ssl_decrypt_buf function in library/ssl_tls.c in PolarSSL before 1.2.11 and 1.3.x before 1.3.8 allows remote attackers to cause a denial of service (crash) via vectors related to the GCM ciphersuites, as demonstrated using the Codenomicon Defensics toolkit.

The RSA-CRT implementation in PolarSSL before 1.2.9 does not properly perform Montgomery multiplication, which might allow remote attackers to conduct a timing side-channel attack and retrieve RSA private keys.

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.