---
id: CVE-2020-21840
title: >-
  A heap based buffer overflow vulnerability exits in GNU LibreDWG 0.10 via
  bit_search_sentinel ../../src/bits.c:1985.
summary: >-
  A heap based buffer overflow vulnerability exits in GNU LibreDWG 0.10 via
  bit_search_sentinel ../../src/bits.c:1985.
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'
cwe:
  - CWE-787
vendor: gnu
product: libredwg
affected:
  - libredwg = 0.10
published: '2021-05-17'
updated: '2026-07-05'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2020-21840'
references:
  - url: 'http://libredwg.com'
    label: cve@mitre.org
  - url: 'https://github.com/LibreDWG/libredwg/issues/188#issuecomment-574493513'
    label: cve@mitre.org
  - url: 'http://gnu.com'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'http://libredwg.com'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://github.com/LibreDWG/libredwg/issues/188#issuecomment-574493513'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.01073
epssPercentile: 0.63423
ingestedAt: '2026-07-05T00:59:26.411Z'
---

## Overview

A heap based buffer overflow vulnerability exits in GNU LibreDWG 0.10 via bit_search_sentinel ../../src/bits.c:1985.

## Affected

- `libredwg = 0.10`

## Remediation

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