The dissect_v9_v10_pdu_data function in epan/dissectors/packet-netflow.c in the Netflow dissector in Wireshark 1.10.x before 1.10.10 and 1.12.x before 1.12.1 refers to incorrect offset and start variables, which allows remote attackers to cause a denial of service (uninitialized memory read and application crash) via a crafted packet.