dbcve.org
LibredwgApplication · Gnu

CVE-2020-21818

HIGH · 8.8 CVSS v3.1 Published 2021-05-17
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
95/100
Remediation priority · Urgent
Public exploit Remotely reachable No privileges

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A heap based buffer overflow vulnerability exists in GNU LibreDWG 0.10.2641 via htmlescape ../../programs/escape.c:48.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A heap-based buffer overflow vulnerability exists in GNU LibreDWG version 0.10.2641 in the htmlescape function within programs/escape.c at line 48. The function fails to properly validate buffer boundaries when processing input, allowing an attacker to write beyond allocated heap memory boundaries.

MitigationUpgrade to a patched version of GNU LibreDWG that addresses the heap overflow in the htmlescape function, or apply bounds checking to prevent buffer overflows in escape.c:48.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
LibredwgApplication
Affected:= 0.10.2641

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check if GNU LibreDWG is installed
    Run 'libredwg --version' or check your package manager for the installed libreDWG package
    Affected if libreDWG is installed and the version is exactly 0.10.2641
  2. Verify the exact version number
    Compare the output from 'libredwg --version' against the affected version 0.10.2641
    Affected if The installed version is 0.10.2641
  3. Check for escape functionality usage
    Inspect any workflows or applications that process DWG files and may invoke the htmlescape function in escape.c
    Affected if The htmlescape function in programs/escape.c line 48 is executed with unsanitized input
  4. Review application logs for crash indicators
    Monitor application or system logs for segmentation faults or heap corruption errors related to libreDWG processing
    Affected if Heap corruption or out-of-bounds memory write errors occur during DWG file processing

You are affected if GNU LibreDWG version 0.10.2641 is installed and processes DWG files that trigger the htmlescape function in escape.c with input exceeding buffer boundaries.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade to a patched version of GNU LibreDWG that addresses the heap overflow in the htmlescape function, or apply bounds checking to prevent buffer overflows in escape.c:48.

Fix this in Libredwg Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA3.0 h
15.0 hours of engineering $2,560
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2020-21818 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
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