Service crash via bit_read_RC heap overflow
Published May 17, 2021 · Updated Jul 9, 2026
Heap-based buffer overflow in GNU LibreDWG 0.10 allows remote attackers to interrupt service via a crafted DWG file. The bit_read_RC function reads from the heap-backed bit chain without sufficient bounds protection when parsing attacker-supplied DWG data, allowing an out-of-bounds access. Exploitation requires delivery of a malicious DWG to a process using LibreDWG and can crash that process; confidentiality or integrity impact is not established by the public description.
Summary
What happened
Heap-based buffer overflow in GNU LibreDWG 0.10 allows remote attackers to interrupt service via a crafted DWG file. The bit_read_RC function reads from the heap-backed bit chain without sufficient bounds protection when parsing attacker-supplied DWG data, allowing an out-of-bounds access. Exploitation requires delivery of a malicious DWG to a process using LibreDWG and can crash that process; confidentiality or integrity impact is not established by the public description.
The record
- CVE
- CVE-2020-21843
- Published
- May 17, 2021
- Updated
- Jul 9, 2026
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-787, T1203
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- May 17, 2021CVE publishedPublication date reported by the CVE source.
- Jul 9, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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What conditions does exploitation require?
What is affected?
Affected products and versions are unavailable in this record.
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.
Public exploit references
- LibreDWG fuzzing proof of concept for issue 188proof of concept · demonstrated
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Technologies
Your stack
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Your stack
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