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Fencer Vulns
high 7.8

CVE-2016-4295 json

When opening a Hangul Hcell Document (.cell) and processing a particular record within the Workbook stream, an index miscalculation leading…

published 2017-01-06 9 y ago modified 2026-06-17 4 mo ago also EUVD-2016-5295

cvss
7.8
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.2%
EPSS 2.2% chance of exploitation in 30 days, percentile 82%
public exploits
0
none known

Summary

When opening a Hangul Hcell Document (.cell) and processing a particular record within the Workbook stream, an index miscalculation leading to a heap overlow can be made to occur in Hancom Office 2014. The vulnerability occurs when processing data for a formula used to render a chart via the HncChartPlugin.hplg library. Due to a lack of bounds-checking when incrementing an index that is used for writing into a buffer for formulae, the application can be made to write pointer data outside its bounds which can lead to code execution under the context of the application.

Exploit prediction

2.22% chance of exploitation in the next 30 days, higher than 82% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • talosintelligence.com http://www.talosintelligence.com/reports/TALOS-2016-0150/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.0 7.8 CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD 2.0 6.8 AV:N/AC:M/Au:N/C:P/I:P/A:P

Affected products

  • Hancom Hancom Office

Classification

Weakness
  • CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.