CVE-2021-40400Public exploitNetwork attack vector

Process-memory disclosure via oversized outline parameter copy

Published Apr 14, 2022 · Updated Apr 15, 2025

Out-of-bounds read in Gerbv 2.7.0 and dev commit b5f1eacd allows attackers to disclose process memory via a crafted Gerber file. The outline-primitive handler derives a copy length from an attacker-controlled vertex count, caps it at 102 parameters, and copies that many doubles from a smaller virtual stack into the simplified macro structure. The file must be parsed as RS-274X and instantiate the malicious aperture macro; a rendering service can return heap-derived shape data in the resulting image.

CVSS severity9.3
Critical
EPSS probability1.29%
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 read in Gerbv 2.7.0 and dev commit b5f1eacd allows attackers to disclose process memory via a crafted Gerber file. The outline-primitive handler derives a copy length from an attacker-controlled vertex count, caps it at 102 parameters, and copies that many doubles from a smaller virtual stack into the simplified macro structure. The file must be parsed as RS-274X and instantiate the malicious aperture macro; a rendering service can return heap-derived shape data in the resulting image.

The record

CVE
CVE-2021-40400
Published
Apr 14, 2022
Updated
Apr 15, 2025
Vendor
Gerbv
Product
Gerbv
Classifications
CWE-119, CWE-125, T1005
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 14, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 15, 2025Record 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=2.7.0
  2. Affected versionversion=dev (commit b5f1eacd)

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Gerbv · Gerbvversion=2.7.0; version=dev (commit b5f1eacd)

Published CVSS scores

7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
5.0NIST NVDAV:N/AC:L/Au:N/C:P/I:N/A:N
9.3Cisco TalosCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/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-125Out-of-bounds Read
T1005Data from Local System

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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