Stack consumption vulnerability in the dissect_ber_unknown function in epan/dissectors/packet-ber.c in the BER dissector in Wireshark 1.4.x before 1.4.1 and 1.2.x before 1.2.12 allows remote attackers to cause a denial of service (NULL pointer dereference and crash) via a long string in an unknown ASN.1/BER encoded packet, as demonstrated using SNMP.