The ascend_seek function in wiretap/ascendtext.c in the Ascend file parser in Wireshark 1.12.x before 1.12.9 and 2.0.x before 2.0.1 does not ensure the presence of a '\0' character at the end of a date string, which allows remote attackers to cause a denial of service (out-of-bounds read and application crash) via a crafted file.