CVE-2020-35633Network attack vector

Code execution via unchecked Nef_S2 boundary index

Published Aug 30, 2021 · Updated Apr 23, 2025

Out-of-bounds read in CGAL 5.1.1 allows attackers to execute code by supplying a malformed Nef_S2 polygon file. In Nef_S2/SNC_io_parser.h, SNC_io_parser::read_sface() passes an unvalidated file-supplied index into Edge_of[] when calling store_sm_boundary_item(). A consuming application must parse attacker-controlled Nef_S2 input; the invalid object reference can crash the process or enable code execution.

CVSS severity10.0
Critical
EPSS probability2.33%
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 CGAL 5.1.1 allows attackers to execute code by supplying a malformed Nef_S2 polygon file. In Nef_S2/SNC_io_parser.h, SNC_io_parser::read_sface() passes an unvalidated file-supplied index into Edge_of[] when calling store_sm_boundary_item(). A consuming application must parse attacker-controlled Nef_S2 input; the invalid object reference can crash the process or enable code execution.

The record

CVE
CVE-2020-35633
Published
Aug 30, 2021
Updated
Apr 23, 2025
Vendor
CGAL Project
Product
CGAL
Classifications
CWE-129, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 30, 2021CVE publishedPublication date reported by the CVE source.
  2. Apr 23, 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=CGAL Project libcgal CGAL-5.1.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

CGAL Project · CGALversion=CGAL Project libcgal CGAL-5.1.1

Published CVSS scores

10.0Cisco TalosCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/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.

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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 exploitUnconfirmed

Weakness, pattern, technique

CWE-129Improper Validation of Array Index
T1203Exploitation for Client Execution

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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