---
id: CVE-2020-21817
title: >-
  A null pointer dereference issue exists in GNU LibreDWG 0.10.2641 via
  htmlescape ../../programs/escape.c:29
summary: >-
  A null pointer dereference issue exists in GNU LibreDWG 0.10.2641 via
  htmlescape ../../programs/escape.c:29. which causes a denial of service
  (application crash).
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H'
cwe:
  - CWE-476
vendor: gnu
product: libredwg
affected:
  - libredwg = 0.10.2641
published: '2021-05-17'
updated: '2026-07-05'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2020-21817'
references:
  - url: 'https://github.com/LibreDWG/libredwg/issues/182#issue-547887727'
    label: cve@mitre.org
  - url: 'http://gnu.com'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://github.com/LibreDWG/libredwg/issues/182#issue-547887727'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.00911
epssPercentile: 0.58336
ingestedAt: '2026-07-05T00:59:26.395Z'
---

## Overview

A null pointer dereference issue exists in GNU LibreDWG 0.10.2641 via htmlescape ../../programs/escape.c:29. which causes a denial of service (application crash).

## Affected

- `libredwg = 0.10.2641`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.