CVE-2023-28771: Zyxel Multiple Firewalls OS Command Injection Vulnerability

Reference page built from the source records below, each shown as its source publishes it. Dataset version ref-f4f189058144, updated 2026-11-02T23:39:54.475Z.

CISA Known Exploited Vulnerabilities

Name
Zyxel Multiple Firewalls OS Command Injection Vulnerability
Vendor
Zyxel
Product
Multiple Firewalls
Added to the catalog
2023-05-31
Due date for US federal agencies
2023-06-21
Weaknesses
CWE-78
Catalog version
2026.10.30

Zyxel ATP, USG FLEX, VPN, and ZyWALL/USG firewalls allow for improper error message handling which could allow an unauthenticated attacker to execute OS commands remotely by sending crafted packets to an affected device.

Required action (CISA)

Apply updates per vendor instructions.

Ransomware use: CISA does not mark known use of this vulnerability in ransomware campaigns.

Links in CISA's notes

Read on 2026-11-02T23:39:54.475Z under licence cisa-kev-cc0@b0067899 from https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json

NVD analysis

Status
Analyzed
Published
2023-04-25T02:15:08.743
Last modified
2026-06-17T05:48:44.217
Weaknesses
CWE-78

Improper error message handling in Zyxel ZyWALL/USG series firmware versions 4.60 through 4.73, VPN series firmware versions 4.60 through 5.35, USG FLEX series firmware versions 4.60 through 5.35, and ATP series firmware versions 4.60 through 5.35, which could allow an unauthenticated attacker to execute some OS commands remotely by sending crafted packets to an affected device.

MetricScoreSeverityVectorScored by
CVSS 3.19.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H[email protected] (Secondary)
CVSS 3.19.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H[email protected] (Secondary)

References

This product uses the NVD API but is not endorsed or certified by the NVD.

Read on 2026-11-02T23:42:08.214Z under licence nvd-api-terms-of-use@ff2a5288 from https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2023-28771

CVE record

Assigner
Zyxel
State
PUBLISHED
Published
2023-04-25T00:00:00.000Z
Updated
2025-10-21T23:05:48.400Z
Problem types
CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

Improper error message handling in Zyxel ZyWALL/USG series firmware versions 4.60 through 4.73, VPN series firmware versions 4.60 through 5.35, USG FLEX series firmware versions 4.60 through 5.35, and ATP series firmware versions 4.60 through 5.35, which could allow an unauthenticated attacker to execute some OS commands remotely by sending crafted packets to an affected device.

References

Read on 2026-11-03T02:03:18.583Z under licence cve-terms-of-use@81bfa2f3 from https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2023/28xxx/CVE-2023-28771.json

Defensive techniques (MITRE D3FEND)

D3FEND maps these defensive techniques to the weakness (CWE) that NVD lists for this CVE, through the digital artifacts the weakness affects. D3FEND does not say they stop this vulnerability.

CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

D3FEND ontology version 1.6.0.

Read on 2026-11-02T23:54:16.526Z under licence d3fend-terms-of-use@f98cbc7e from https://d3fend.mitre.org/api/weakness/cwe/CWE-78.json

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Sources and licences

  • CISA

    Source: CISA Catalog of Known Exploited Vulnerabilities, version 2026.10.30, CC0 1.0. Use of this data does not imply endorsement by CISA or DHS.

    CC0 1.0 Universal

  • National Vulnerability Database (NIST)

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    NVD API Terms of Use (NIST publications in the public domain, 17 U.S.C. 105)

  • CVE Program, The MITRE Corporation

    Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation. CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy.

    CVE Program Terms of Use ("CVE Usage" licence)

  • MITRE D3FEND

    MITRE D3FEND™ knowledge graph. © 2025 The MITRE Corporation.
    "The MITRE Corporation (MITRE) hereby grants you a non-exclusive, royalty-free license to use D3FEND for research, development, and commercial purposes. Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." Terms: https://d3fend.mitre.org/tou/

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Cite this page

Dragons Eye Ransomware Tracker, "CVE-2023-28771: Zyxel Multiple Firewalls OS Command Injection Vulnerability",
entity page, dataset version ref-f4f189058144, updated 2026-11-02T23:39:54.475Z,
https://ransomware-tracker.com/cve/CVE-2023-28771 (accessed 2026-11-03).
Underlying source: CISA Catalog of Known Exploited Vulnerabilities, version 2026.10.30.
Underlying source: National Vulnerability Database (NIST), CVE API 2.0, record last modified 2026-06-17T05:48:44.217.
Underlying source: CVE List (CVE Program, The MITRE Corporation), record updated 2025-10-21T23:05:48.400Z.
Underlying source: MITRE D3FEND, ontology version 1.6.0.

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