CVE-2021-21958 Memory corruption in Hancom
A heap-based buffer overflow in Hancom Office allows attackers to execute arbitrary code via a specially crafted file.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2021-21958?
CVE-2021-21958 is a high-severity memory corruption vulnerability in Hancom, published on 16 Feb 2022. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official 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.
Which versions are affected by CVE-2021-21958?
It affects 1 product.
Products include Hancom Hancom Office 2020.
How do I fix CVE-2021-21958?
No fix has been published for CVE-2021-21958 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2021-21958 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-21958 exists.
Other vulnerabilities in Hancom
Sources
Also known as GHSA-5fcw-h565-mjpq.