CVE-2021-21958
CVE-2021-21958 is a high-severity vulnerability in Hancom Hancom Office 2020 with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-787.
Key facts
- Severity: High (CVSS 3.x base score 7.8)
- CVSS v2: 6.8
- EPSS exploit prediction: 1% (62nd percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-787
- Affected product: Hancom Hancom Office 2020
- Published:
- Last modified:
Description
A heap-based buffer overflow vulnerability exists in the Hword HwordApp.dll functionality of Hancom Office 2020 11.0.0.2353. A specially-crafted malformed file can lead to memory corruption and potential arbitrary code execution. An attacker can provide a malicious file to trigger this vulnerability.
Frequently asked questions
- What is CVE-2021-21958?
- A heap-based buffer overflow vulnerability exists in the Hword HwordApp.dll functionality of Hancom Office 2020 11.0.0.2353. A specially-crafted malformed file can lead to memory corruption and potential arbitrary code execution. An attacker can provide a malicious file to trigger this vulnerability.
- How severe is CVE-2021-21958?
- CVE-2021-21958 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
- Is CVE-2021-21958 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (62nd percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2021-21958?
- CVE-2021-21958 affects Hancom Hancom Office 2020. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2021-21958?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- When was CVE-2021-21958 published?
- CVE-2021-21958 was published on 2022-02-16 and last updated on 2026-06-17.
References
- https://talosintelligence.com/vulnerability_reports/TALOS-2021-1386
- https://blog.talosintelligence.com/2022/02/vuln-spotlight-.html
Affected products (1)
- cpe:2.3:a:hancom:hancom_office_2020:11.0.0.2353:*:*:*:*:*:*:*
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