CVE-2021-45950Network attack vector

Denial of service via out-of-bounds write

Published Dec 31, 2021 · Updated Aug 4, 2024

Out-of-bounds write in LibreDWG 0.12.4.4313 through 0.12.4.4367 allows remote attackers to interrupt service via crafted DWG files. The dwg_free_BLOCK_private routine writes beyond an allocated object while freeing BLOCK data, reached through dwg_free_BLOCK and dwg_free_object during DWG processing. Exploitation requires a victim to open or process attacker-supplied DWG content; the documented consequence is a high-impact service crash without confidentiality or integrity loss.

CVSS severity6.5
Medium
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

Out-of-bounds write in LibreDWG 0.12.4.4313 through 0.12.4.4367 allows remote attackers to interrupt service via crafted DWG files. The dwg_free_BLOCK_private routine writes beyond an allocated object while freeing BLOCK data, reached through dwg_free_BLOCK and dwg_free_object during DWG processing. Exploitation requires a victim to open or process attacker-supplied DWG content; the documented consequence is a high-impact service crash without confidentiality or integrity loss.

The record

CVE
CVE-2021-45950
Published
Dec 31, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-787, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 31, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record 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 vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

4.3NVDAV:N/AC:M/Au:N/C:N/I:N/A:P
6.5NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1203Exploitation for Client Execution

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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