Integer Overflow or Wraparound
When opening a Hangul HShow Document (.hpt) and processing a structure within the document, Hancom Office 2014 will use a field from the structure in an operation that can cause the integer to overflow. This result is then used to allocate memory to copy file data in. Due to the lack of bounds checking on the integer, the allocated memory buffer can be made to be undersized at which point the reading of file data will write outside the bounds of the buffer. This can lead to code execution under the context of the application.
CWE-190 - Integer Overflow or Wraparound
The software performs a calculation that can produce an integer overflow or wraparound, when the logic assumes that the resulting value will always be larger than the original value. This can introduce other weaknesses when the calculation is used for resource management or execution control.