Zyxel NAS326/NAS542 Web Server os command injection

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
9.8$5k-$25k0.00

Summaryinfo

A vulnerability was found in Zyxel NAS326 and NAS542. It has been declared as critical. Affected by this vulnerability is an unknown functionality of the component Web Server. The manipulation results in os command injection. This vulnerability was named CVE-2023-4473. The attack may be performed from remote. There is no available exploit.

Detailsinfo

A vulnerability, which was classified as very critical, was found in Zyxel NAS326 and NAS542 (version now known). Affected is some unknown processing of the component Web Server. The manipulation with an unknown input leads to a os command injection vulnerability. CWE is classifying the issue as CWE-78. The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

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.

The weakness was presented 11/30/2023. The advisory is available at zyxel.com. This vulnerability is traded as CVE-2023-4473 since 08/22/2023. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $5k-$25k at the moment (estimation calculated on 12/16/2025). This vulnerability is assigned to T1202 by the MITRE ATT&CK project.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2023-54328). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Vendor

Name

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.8
VulDB Meta Temp Score: 9.8

VulDB Base Score: 9.8
VulDB Temp Score: 9.8
VulDB Vector: 🔍
VulDB Reliability: 🔍

CNA Base Score: 9.8
CNA Vector (Zyxel Corporation): 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Os command injection
CWE: CWE-78 / CWE-77 / CWE-74
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔍

Timelineinfo

08/22/2023 🔍
11/30/2023 +100 days 🔍
11/30/2023 +0 days 🔍
12/16/2025 +747 days 🔍

Sourcesinfo

Vendor: zyxel.com

Advisory: zyxel.com
Status: Confirmed

CVE: CVE-2023-4473 (🔍)
GCVE (CVE): GCVE-0-2023-4473
GCVE (VulDB): GCVE-100-246378
EUVD: 🔍

Entryinfo

Created: 11/30/2023 06:47
Updated: 12/16/2025 19:50
Changes: 11/30/2023 06:47 (47), 12/16/2025 19:50 (16)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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