Zyxel NAS326/NAS542 WSGI Server os command injection

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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9.8$5k-$25k0.00

Summaryinfo

A vulnerability classified as critical has been found in Zyxel NAS326 and NAS542. The impacted element is an unknown function of the component WSGI Server. This manipulation causes os command injection. This vulnerability is registered as CVE-2023-4474. Remote exploitation of the attack is possible. No exploit is available.

Detailsinfo

A vulnerability classified as very critical was found in Zyxel NAS326 and NAS542 (version now known). Affected by this vulnerability is some unknown processing of the component WSGI Server. The manipulation with an unknown input leads to a os command injection vulnerability. The CWE definition for the vulnerability is 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. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

The improper neutralization of special elements in the WSGI 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 published 11/30/2023. The advisory is shared at zyxel.com. This vulnerability is known as CVE-2023-4474 since 08/22/2023. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 12/16/2025). MITRE ATT&CK project uses the attack technique T1202 for this issue.

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-2023-54329). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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-2023-4474 (🔍)
GCVE (CVE): GCVE-0-2023-4474
GCVE (VulDB): GCVE-100-246385
EUVD: 🔍

Entryinfo

Created: 11/30/2023 06:55
Updated: 12/16/2025 19:50
Changes: 11/30/2023 06:55 (47), 12/16/2025 19:50 (16)
Complete: 🔍
Cache ID: 216::103

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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