Security readout for executives and security teams
Plain-English summary
CVE-2021-40400 affects Gerbv, a Gerber file viewer/parser used in PCB workflows. A malicious Gerber file can trigger an out-of-bounds read, potentially causing information disclosure and severe application impact. The provided sources do not show active exploitation or a named patch.
Executive priority
Prioritize this where Gerber files enter from outside the organization or support revenue-critical PCB workflows. Treat internet-facing or automated file-processing paths as urgent. Internal-only desktop use is still important but depends on trust boundaries and file sources.
Technical view
The flaw is an out-of-bounds read in RS-274X aperture macro outline primitive handling in Gerbv 2.7.0, Gerbv dev commit b5f1eacd, and a forked Gerbv commit d7f42a9a. CVSS 3.0 is 9.3 with low attack complexity, no privileges, changed scope, low confidentiality impact, and high availability impact.
Likely exposure
Exposure is most likely where Gerbv or the named fork processes Gerber files from customers, suppliers, public uploads, email attachments, or automated PCB pipelines. Confirm exact versions and commits before treating a system as affected.
Exploitation context
The bundle says an attacker can provide a specially crafted Gerber file to trigger the issue. It does not cite known exploitation, and KEV status is false. No weaponized details or public exploit status are provided in the supplied sources.
Researcher notes
Evidence supports the affected versions, parser area, and malicious-file trigger. The supplied bundle does not name a fixed version, workaround, exploit availability, or exploitation in the wild. Remediation should be tied to current Gerbv project guidance before closure.
Mitigation direction
- Inventory Gerbv and forked Gerbv usage across PCB workflows.
- Check project or vendor guidance for fixed releases or commits.
- Avoid processing untrusted Gerber files with affected builds.
- Isolate unavoidable Gerber parsing from sensitive systems and data.
- Restrict file intake to trusted business channels where possible.
Validation and detection
- Confirm whether Gerbv 2.7.0 is installed anywhere.
- Check dev builds for commit b5f1eacd or fork commit d7f42a9a.
- Map systems that accept Gerber files from external parties.
- Review crash reports around Gerber file parsing workflows.
- Document whether compensating isolation controls are in place.
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
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ATT&CK lookup starting points
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CWE-119: Exact CWE lookup
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Open ATT&CK lookupCVE-2021-40400 mapping review
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Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.3 (3.0)
- Known Exploited
- No
- Published
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:H
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 vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:H3.94.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.0 score
9.3CriticalVector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://talosintelligence.com/vulnerability_reports/TALOS-2021-1413CVE 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.