CVE-2020-21814
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 · uneditedA heap based buffer overflow issue exists in GNU LibreDWG 0.10.2641 via htmlwescape ../../programs/escape.c:97.
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 confidenceA heap-based buffer overflow vulnerability exists in GNU LibreDWG version 0.10.2641 within the htmlwescape function in programs/escape.c at line 97. This occurs due to insufficient bounds checking when handling HTML escape sequences, potentially allowing an attacker to overwrite heap memory and achieve code execution or cause denial of service.
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= 0.10.2641CVSS 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 checksWork through these to decide whether this CVE applies to you.
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Identify installed GNU LibreDWG versionRun 'libredwg --version' or check the package version installed via your system's package manager (dpkg, rpm, brew, etc.)Affected if Version is exactly 0.10.2641
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Locate the vulnerable escape.c fileSearch for programs/escape.c in the LibreDWG source directory or installation pathAffected if File exists and contains the htmlwescape function definition near line 97
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Verify the vulnerable code patternOpen escape.c and examine the htmlwescape function for missing bounds checking around line 97 when handling HTML escape sequencesAffected if The code shows insufficient bounds checking before writing to the destination buffer
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Check for HTML input processingIdentify if any application or tool using LibreDWG processes HTML escape sequences or uses the htmlwescape function with user-controlled inputAffected if The htmlwescape function is invoked with untrusted HTML content that could overflow the buffer
You are affected if LibreDWG version 0.10.2641 is installed and the htmlwescape function in programs/escape.c processes HTML content without proper bounds validation.
Generated from the published advisory. Verify against your own configuration.
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 dataUpgrade to a patched version of GNU LibreDWG that addresses the heap overflow in the htmlwescape function, or implement proper input validation and bounds checking in escape.c to ensure buffer limits are enforced.
- Consultation4.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA3.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,408.
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Free · runs locallyCheck whether your project pulls in CVE-2020-21814 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2020-21814 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Version or environment caveats, and links to real fixes
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