The dissect_atn_cpdlc_heur function in asn1/atn-cpdlc/packet-atn-cpdlc-template.c in the ATN-CPDLC dissector in Wireshark 1.12.x before 1.12.4 does not properly follow the TRY/ENDTRY code requirements, which allows remote attackers to cause a denial of service (stack memory corruption and application crash) via a crafted packet.