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.