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FedoraOperating system · Fedoraproject

CVE-2020-28601

CRITICAL · 9.8 CVSS v3.1 Published 2021-03-04
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A code execution vulnerability exists in the Nef polygon-parsing functionality of CGAL libcgal CGAL-5.1.1. An oob read vulnerability exists in Nef_2/PM_io_parser.h PM_io_parser::read_vertex() Face_of[] OOB read. An attacker can provide malicious input to trigger this vulnerability.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A critical code execution vulnerability exists in CGAL library's Nef polygon-parsing functionality. The specific issue is an out-of-bounds read in PM_io_parser::read_vertex() when accessing the Face_of[] array in Nef_2/PM_io_parser.h, allowing attackers to trigger memory corruption via maliciously crafted polygon input files.

MitigationUpdate CGAL to a patched version that addresses the OOB read in PM_io_parser::read_vertex(). If patching is not immediately possible, sanitize or restrict input files processed by the Nef polygon-parsing functionality until the update can be applied.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
FedoraOperating system
Affected:= 33= 34
Debian LinuxOperating system
Affected:= 9.0= 10.0
Computational Geometry Algorithms LibraryApplication
Affected:= 5.1.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify installed CGAL version
    On Debian/Ubuntu: dpkg -l | grep cgal or apt show libcgal-dev. On Fedora/RHEL: rpm -qa | grep cgal. Alternatively, check the library file version if CGAL is linked as a shared library.
    Affected if The installed version matches 5.1.1 or falls within the affected ranges on Fedora 33/34 or Debian 9/10.
  2. Check if Nef polygon-parsing is in use
    Search source code for includes of PM_io_parser.h or Nef_2 headers, or for usage of Nef_2::PM_io_parser class. Look for references to 'read_vertex' function in code that handles polygon file parsing.
    Affected if Code references PM_io_parser or Nef_2 polygon-parsing functionality for processing input files.
  3. Audit polygon input files
    Review application logs, temp directories, or upload directories for .polygon, .nef, or custom polygon format files that may be processed by CGAL's Nef parser.
    Affected if The application processes untrusted polygon input files through CGAL's Nef functionality.
  4. Verify application linking to vulnerable CGAL
    Use ldd on the application binary or check build artifacts for linkage to libCGAL. If source is available, check CMakeLists.txt or Makefile for CGAL version requirements.
    Affected if The application links to CGAL version 5.1.1 or an unpatched version from affected distributions.

If CGAL 5.1.1 is installed on Fedora 33/34 or Debian 9/10 and the application uses the Nef polygon-parsing (PM_io_parser) to process polygon input files, the environment is vulnerable to the OOB read in PM_io_parser::read_vertex.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Update CGAL to a patched version that addresses the OOB read in PM_io_parser::read_vertex(). If patching is not immediately possible, sanitize or restrict input files processed by the Nef polygon-parsing functionality until the update can be applied.

Recommended fix High confidence

CGAL version 5.2 or later (the next stable release after 5.1.1 contains the security fix)

  1. Identify the specific CGAL library version in use by examining project dependencies or installed packages
  2. Locate the CGAL library in the system (typically in /usr/lib/ or via package manager: rpm -qa | grep cgal or dpkg -l | grep cgal)
  3. For Fedora systems: Run 'dnf update cgal' or 'dnf upgrade cgal' to obtain the latest patched version
  4. For Debian systems: Run 'apt-get update && apt-get upgrade libcgal-dev' to get the patched version
  5. If using CGAL as a project dependency (e.g., via Conan, vcpkg, or other package managers), update the dependency specification to a version newer than 5.1.1
  6. Verify the update was successful by checking the new CGAL version: rpm -qa | grep cgal (Fedora) or dpkg -l | grep libcgal (Debian)
  7. Rebuild any applications that statically link against CGAL to ensure they use the updated library
  8. Test applications that use CGAL's Nef polygon-parsing functionality to confirm the vulnerability is mitigated
Caveat Minor API additions in CGAL 5.2; review CGAL 5.2 release notes for any deprecation warnings relevant to Nef polygon-parsing code

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Fedora Scoped from the published advisory
  • Consultation3.0 h
  • Implementation6.0 h
  • Testing5.0 h
  • Review / QA2.0 h
16.0 hours of engineering $2,790
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2020-28601 in production — separate from our analysis above.

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What this is

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What belongs here
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  • Version or environment caveats, and links to real fixes
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