dbcve.org
LibredwgApplication · Gnu

CVE-2020-21819

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 0.10.2641via htmlescape ../../programs/escape.c:51.

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 0.10.2641 within the htmlescape function in programs/escape.c at line 51. The htmlescape function, responsible for HTML escaping operations, does not properly validate buffer boundaries when processing input, allowing an attacker to overflow the heap allocation and potentially achieve arbitrary code execution.

MitigationUpdate GNU LibreDWG to the latest patched version. If immediate updating is not feasible, implement input validation and bounds checking in the htmlescape function to prevent buffer overflows, and/or deploy compensating controls such as input sanitization at the application layer before data reaches the vulnerable function.

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. Identify if GNU LibreDWG is installed
    Run command: dpkg -l | grep libredwg (Debian/Ubuntu), rpm -qa | grep libredwg (RHEL/CentOS), or brew list libredwg (macOS). Also check for files matching 'libredwg*' in common library directories like /usr/lib/, /usr/local/lib/, or /opt/.
    Affected if GNU LibreDWG library files are found on the system
  2. Determine the installed version of GNU LibreDWG
    Run: libredwg --version or check the library file version with: strings /path/to/libredwg.so | grep -i version. Compare the version number to 0.10.2641.
    Affected if The installed version is exactly 0.10.2641
  3. Locate the escape.c source file or compiled escape module
    Search for escape.c or escape.o in source directories and compiled binaries: find / -name 'escape.c' 2>/dev/null | xargs grep -l 'htmlescape' 2>/dev/null. Check if programs using LibreDWG link against the escape module.
    Affected if The htmlescape function from programs/escape.c is present and being used by any application on the system
  4. Identify applications or tools that use the LibreDWG library
    Check for binaries that depend on libredwg: ldd /path/to/binary 2>/dev/null | grep libredwg, or scan /usr/bin/, /usr/local/bin/ for applications that process DWG files and depend on this library.
    Affected if Any application that processes DWG files and links to the vulnerable LibreDWG library is in use

A system is affected only if GNU LibreDWG version 0.10.2641 is installed AND any application invokes the htmlescape function from programs/escape.c to process DWG file data.

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 GNU LibreDWG to the latest patched version. If immediate updating is not feasible, implement input validation and bounds checking in the htmlescape function to prevent buffer overflows, and/or deploy compensating controls such as input sanitization at the application layer before data reaches the vulnerable function.

Recommended fix Moderate confidence

Any stable release newer than 0.10.2641 (check GitHub releases for version containing the fix)

  1. 1. Visit the LibreDWG releases page at https://github.com/LibreDWG/libredwg/releases to identify a version newer than 0.10.2641 that includes the security fix for CVE-2020-21819
  2. 2. Review the release notes or changelog for the fixed version to confirm the vulnerability is addressed
  3. 3. Download the source code or pre-built packages for the fixed release
  4. 4. Uninstall the vulnerable version (0.10.2641) if installed
  5. 5. Build and install the new version following the project's build instructions (typically ./configure, make, make install)
  6. 6. Verify the installation by running `dwggrep --version` or similar to confirm the new version is active
  7. 7. Test that any DWG-related tools function correctly with the updated library
Caveat Minor - this is a bugfix release; verify any custom integrations with LibreDWG API remain compatible

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
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
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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-2020-21819 in production — separate from our analysis above.

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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
  • No spam, self-promotion, credentials, or personal data