CVE-2022-33896Public exploit

Code execution via unmatched DOCX paragraph tag

Published Oct 7, 2022 · Updated Apr 15, 2025

Buffer underflow in Hword in Hancom Office 2020 11.0.0.5357 allows attackers to execute code by opening a malformed DOCX file. When word/document.xml contains a closing paragraph tag without its opening tag, Hword assumes another vector element exists, subtracts four bytes from a heap pointer, and uses the preceding value for an indirect call. A victim must open the crafted document; successful exploitation executes code in the victim's process context.

CVSS severity7.8
High
EPSS probability0.52%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Buffer underflow in Hword in Hancom Office 2020 11.0.0.5357 allows attackers to execute code by opening a malformed DOCX file. When word/document.xml contains a closing paragraph tag without its opening tag, Hword assumes another vector element exists, subtracts four bytes from a heap pointer, and uses the preceding value for an indirect call. A victim must open the crafted document; successful exploitation executes code in the victim's process context.

The record

CVE
CVE-2022-33896
Published
Oct 7, 2022
Updated
Apr 15, 2025
Vendor
Hancom Inc.
Product
Hancom Office 2020
Classifications
CWE-124, T1203, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 7, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 15, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Hancom Office 2020 11.0.0.5357

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Hancom Inc. · Hancom Office 2020version=Hancom Office 2020 11.0.0.5357

Published CVSS scores

7.8Cisco TalosCVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-124Buffer Underwrite ('Buffer Underflow')
T1203Exploitation for Client Execution
T1204.002User Execution: Malicious File

Public exploit references

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Technologies

Your stack

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Your stack

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