Security readout for executives and security teams
Plain-English summary
LibreDWG versions through v0.10.1.3751 can crash when processing a crafted DWG file. The documented impact is denial of service, not data theft or remote code execution. Business urgency depends on whether DWG files from untrusted users, customers, or partners are parsed in production workflows.
Executive priority
Prioritize if DWG parsing is internet-facing, customer-facing, or business-critical. Otherwise handle in normal vulnerability maintenance, because the known impact is service disruption and the sources do not show active exploitation.
Technical view
CVE-2021-39523 is a NULL pointer dereference in check_POLYLINE_handles() in decode.c in LibreDWG through v0.10.1.3751. The source description says an attacker can cause denial of service. The bundle provides no CVSS score, CWE mapping, fixed version, or confirmed exploitation evidence.
Likely exposure
Exposure is most likely in applications, batch processors, or services using LibreDWG to decode DWG files, especially where files are user-supplied or partner-supplied. Systems that do not process untrusted DWG content have lower practical exposure.
Exploitation context
The CVE is not listed as KEV in the supplied bundle, and no cited source confirms active exploitation. The public issue reference indicates a crash-class parsing flaw. Treat exploitability as denial of service only unless vendor guidance says otherwise.
Researcher notes
Evidence is limited to the CVE description and the referenced LibreDWG issue. No CVSS vector, CWE, patch version, or exploitation status is provided in the source bundle. Avoid expanding impact beyond NULL pointer dereference denial of service.
Mitigation direction
- Check LibreDWG project guidance for a fixed release or recommended workaround.
- Reduce or block untrusted DWG parsing until remediation is confirmed.
- Run DWG processing in isolated workers with resource and restart controls.
- Limit upload sources and apply file-handling controls around DWG ingestion.
Validation and detection
- Inventory all applications and services using LibreDWG.
- Confirm whether any deployed version is through v0.10.1.3751.
- Identify workflows that parse DWG files from untrusted sources.
- Review service logs for crashes during DWG decoding.
- Track the GitHub issue and CVE record for remediation updates.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CVE-2021-39523 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/LibreDWG/libredwg/issues/251CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.