dbcve.org
LibredwgApplication · Gnu

CVE-2020-21831

HIGH · 8.8 CVSS v3.1 Published 2021-05-17
Patch available
A vendor patch is available. No clean upgrade release — apply the published patch.
See remediation →
95/100
Remediation priority · Urgent
Public exploit Remotely reachable No privileges Patch available

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 via read_2004_section_handles ../../src/decode.c:2637.

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 · moderate confidence

A heap-based buffer overflow vulnerability exists in GNU LibreDWG version 0.10 in the read_2004_section_handles function within decode.c at line 2637. The vulnerability occurs during DWG file parsing when handling section handles, allowing potential code execution or denial of service via specially crafted DWG files.

MitigationUpdate to a patched version of GNU LibreDWG. Until then, avoid processing DWG files from untrusted sources and implement input validation to reject malformed DWG files.

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

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 installed LibreDWG version
    Run 'redwg --version' or 'libredwg-config --version' to identify the installed version. If using a package manager, query the installed package version.
    Affected if The installed version is exactly 0.10 (GNU Libredwg version 0.10)
  2. Identify DWG processing tools or libraries
    Search for binaries or libraries linked against libredwg (for example, look for 'libredwg.so' or 'libredwg.a' in system directories, or check for applications that import DWG files).
    Affected if LibreDWG library version 0.10 is present on the system and used by any application
  3. Determine if DWG file parsing is in use
    Review application logs or look for recent DWG file processing activity. Check for applications that accept .dwg file input, such as CAD viewers, converters, or document processing tools that depend on LibreDWG.
    Affected if Any application uses LibreDWG version 0.10 to parse DWG files from any source

A system is affected if GNU LibreDWG version 0.10 is installed and any application uses it to parse DWG files, as the heap overflow triggers during the read_2004_section_handles operation in decode.c.

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.

dbcve · scoped
Patch available Apply the vendor patch
Vendor patch github.com →
Interim mitigation

Update to a patched version of GNU LibreDWG. Until then, avoid processing DWG files from untrusted sources and implement input validation to reject malformed DWG files.

Recommended fix Moderate confidence

Upgrade to the latest stable release of LibreDWG (version higher than 0.10). Check the GitHub releases page for version 0.10.1 or later that contains the security fix.

  1. 1. Navigate to the official LibreDWG repository at https://github.com/LibreDWG/libredwg
  2. 2. Check the Releases page to identify the latest stable version that includes the fix for CVE-2020-21831
  3. 3. If using a package manager (e.g., apt, yum, brew), check for available package updates that include the patched version
  4. 4. Download the source code of the fixed version or update via package manager
  5. 5. Rebuild/reinstall Libredwg according to the project's build instructions
  6. 6. Verify the installation by running `dwg --version` to confirm the updated version is installed
  7. 7. Test that the previously vulnerable functionality works correctly with the updated version
Caveat Review release notes for any breaking changes between version 0.10 and the target upgrade version before upgrading.

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Libredwg Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing6.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,380
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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-2020-21831 in production — separate from our analysis above.

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What this is

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What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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