CVE-2020-21827Public exploit

Application crash via unchecked compressed-section memcpy

Published May 17, 2021 · Updated Jul 9, 2026

Heap-based buffer overflow in GNU LibreDWG 0.10 allows attackers to crash a consuming application with a crafted DWG file. During R2004 compressed-section parsing, read_2004_compressed_section passes an unchecked section size to memcpy, writing past the allocated decompression buffer. Processing the file is required, and the demonstrated consequence is an AddressSanitizer-detected crash rather than a confirmed code-execution path.

CVSS severity7.8
High
EPSS probability0.89%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap-based buffer overflow in GNU LibreDWG 0.10 allows attackers to crash a consuming application with a crafted DWG file. During R2004 compressed-section parsing, read_2004_compressed_section passes an unchecked section size to memcpy, writing past the allocated decompression buffer. Processing the file is required, and the demonstrated consequence is an AddressSanitizer-detected crash rather than a confirmed code-execution path.

The record

CVE
CVE-2020-21827
Published
May 17, 2021
Updated
Jul 9, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 17, 2021CVE publishedPublication date reported by the CVE source.
  2. Jul 9, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.8NIST NVDAV:N/AC:M/Au:N/C:P/I:P/A:P
7.8NIST NVDCVSS:3.1/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1204.002User Execution: Malicious File

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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