Integer overflow in Hancom Office

CVE-2016-4290

When opening a Hangul HShow Document (.hpt) and processing a structure within the document, Hancom Office 2014 will attempt to allocate space for a block of data within the file. When calculating this length, the application will use a value from the file and add a constant to it without checking whether the addition of the constant will cause the integer to overflow which will cause the buffer to be undersized when the application tries to copy file data into it. This allows one to overwrite contiguous data in the heap which can lead to code-execution under the context of the application.

Vulnerability class: Integer Overflow

EPSS: 0.021 (80.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

  • cret@cert.org (Technical Description, Exploit, VDB Entry, Third Party Advisory, x_refsource_MISC)
  • cret@cert.org (vdb-entry, x_refsource_BID)

Frequently asked questions

What is CVE-2016-4290?
CVE-2016-4290 is a high-severity vulnerability in Hancom Office, classified under Integer Overflow or Wraparound. CVSS score: 7.8/10. Published 2017-01-06.
How severe is CVE-2016-4290?
High severity. CVSS v3 base score is 7.8 out of 10.