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.
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.