CVE-2021-40393Public exploitNetwork attack vector

Code execution via unchecked macro-variable array index

Published Dec 22, 2021 · Updated Aug 4, 2024

Out-of-bounds write in Gerbv 2.7.0 and development commits b5f1eacd and 71493260 allows remote attackers to execute code via a crafted Gerber file. In simplify_aperture_macro, numeric variable names index the fixed-size lp parameter array without bounds checks during PPOP assignments. Processing the file through the GUI or command-line exporter is sufficient; a malicious negative index writes attacker-selected double data outside the array, causing a crash or arbitrary code execution.

CVSS severity10.0
Critical
EPSS probability3.06%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds write in Gerbv 2.7.0 and development commits b5f1eacd and 71493260 allows remote attackers to execute code via a crafted Gerber file. In simplify_aperture_macro, numeric variable names index the fixed-size lp parameter array without bounds checks during PPOP assignments. Processing the file through the GUI or command-line exporter is sufficient; a malicious negative index writes attacker-selected double data outside the array, causing a crash or arbitrary code execution.

The record

CVE
CVE-2021-40393
Published
Dec 22, 2021
Updated
Aug 4, 2024
Vendor
Gerbv
Product
Gerbv
Classifications
CWE-119, CWE-787, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 22, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Gerbv 2.7.0, Gerbv dev (commit b5f1eacd),Gerbv forked dev (commit 71493260)

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Gerbv · Gerbvversion=Gerbv 2.7.0, Gerbv dev (commit b5f1eacd),Gerbv forked dev (commit 71493260)

Published CVSS scores

7.5NIST National Vulnerability DatabaseAV:N/AC:L/Au:N/C:P/I:P/A:P
10.0Cisco TalosCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
9.8NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-119Improper Restriction of Operations within the Bounds of a Memory Buffer
CWE-787Out-of-bounds Write
T1203Exploitation for Client Execution

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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