Buffer overflow in Hancom Office

CVE-2016-4296

When opening a Hangul Hcell Document (.cell) and processing a record that uses the CSSValFormat object, Hancom Office 2014 will search for an underscore ("_") character at the end of the string and write a null terminator after it. If the character is at the very end of the string, the application will mistakenly write the null-byte outside the bounds of its destination. This can result in heap corruption that can lead code execution under the context of the application

Vulnerability class: Buffer Overflow

EPSS: 0.022 (80.9th 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-2016-4296?
CVE-2016-4296 is a high-severity vulnerability in Hancom Office, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 7.8/10. Published 2017-01-06.
How severe is CVE-2016-4296?
High severity. CVSS v3 base score is 7.8 out of 10.