CVE-2023-4473 (GCVE-0-2023-4473)

Vulnerability from cvelistv5 – Published: 2023-11-30 01:40 – Updated: 2025-12-16 18:23
VLAI Shadowserver
Summary
A command injection vulnerability in the web server of the Zyxel NAS326 firmware version V5.21(AAZF.14)C0 and NAS542 firmware version V5.21(ABAG.11)C0 could allow an unauthenticated attacker to execute some operating system (OS) commands by sending a crafted URL to a vulnerable device.
Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
SSVC
Exploitation: poc Automatable: yes Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2024-05-03 04:00 UTC
CWE
  • CWE-78 - Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')
Assigner
Zyxel CNA under the mitre root
CNA scorecard C 67/100 over 15 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Zyxel NAS326 firmware Affected: V5.21(AAZF.14)C0
guessed Create a notification for this product.
Zyxel NAS542 firmware Affected: V5.21(ABAG.11)C0
guessed Create a notification for this product.
zyxel nas326_firmware Affected: 5.21\(aazf.14\)c0
    cpe:2.3:o:zyxel:nas326_firmware:5.21\(aazf.14\)c0:*:*:*:*:*:*:*
Create a notification for this product.
zyxel nas542_firmware Affected: 5.21\(abag.11\)c0
    cpe:2.3:o:zyxel:nas542_firmware:5.21\(abag.11\)c0:*:*:*:*:*:*:*
Create a notification for this product.
Shadowserver
Known Exploited Vulnerability - GCVE BCP-07 Compliant
KEV entry ID: 2ae06303-6a76-45ad-b39a-29dba97c1bb9

Vulnerability ID: CVE-2023-4473

Status: Confirmed

Status Updated: 2024-04-30 00:00 UTC

Exploited: Yes

Characteristics
Severity: 98.0
Timestamps
First Seen: 2024-04-28
Asserted: 2024-04-28
Last Seen: 2024-04-30
Scope
Asset Exposure: ['internet-facing']
Notes: Affected: Zyxel / Zyxel NAS326/NAS542 | Class: nas | Severity: Critical (CVSS 9.8) | IoT: yes | In CISA KEV: no | Honeypot connections on 2024-04-30: 333
Evidence

Type: Honeypot

Signal: In The Wild Attempts

Confidence: 70%

Source: shadowserver

Details
1D 1
Iot yes
Feed Shadowserver Foundation honeypot/exploited-vulnerabilities
Type http-scan
Class nas
7D Avg 0
Vendor Zyxel
30D Avg 0
90D Avg 0
Product Zyxel NAS326/NAS542
Cisa Kev no
Connections 333
Observation Date 2024-04-30
Vulnerability Class CVSS
Vulnerability Score 9.8
Vulnerability Severity Critical
References
Created: 2026-07-01 09:12 UTC | Updated: 2026-07-01 13:15 UTC
Show details on NVD website
To clipboard 

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      "cveMetadata": {
        "assignerOrgId": "96e50032-ad0d-4058-a115-4d2c13821f9f",
        "assignerShortName": "Zyxel",
        "cveId": "CVE-2023-4473",
        "datePublished": "2023-11-30T01:40:09.117Z",
        "dateReserved": "2023-08-22T06:51:30.982Z",
        "dateUpdated": "2025-12-16T18:23:26.188Z",
        "state": "PUBLISHED"
      },
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}



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Taxonomy of the tags.




Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.

Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

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    Related by attack behaviour

    Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.