Zyxel ATP/USG FLEX/VPN Logs Page cross site scripting

CVSS Meta Temp Score
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CTI Interest Score
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4.0$0-$5k0.00

Summaryinfo

A vulnerability was found in Zyxel ATP, USG FLEX and VPN. It has been declared as problematic. This impacts an unknown function of the component Logs Page. Such manipulation leads to cross site scripting. This vulnerability is traded as CVE-2023-27990. The attack may be launched remotely. There is no exploit available.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in Zyxel ATP, USG FLEX and VPN (Network Encryption Software) (version now known). Affected by this issue is some unknown processing of the component Logs Page. The manipulation with an unknown input leads to a cross site scripting vulnerability. Using CWE to declare the problem leads to CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. Impacted is integrity. CVE summarizes:

The cross-site scripting (XSS) vulnerability in Zyxel ATP series firmware versions 4.32 through 5.35, USG FLEX series firmware versions 4.50 through 5.35, USG FLEX 50(W) firmware versions 4.16 through 5.35, USG20(W)-VPN firmware versions 4.16 through 5.35, and VPN series firmware versions 4.30 through 5.35, which could allow an authenticated attacker with administrator privileges to store malicious scripts in a vulnerable device. A successful XSS attack could then result in the stored malicious scripts being executed when the user visits the Logs page of the GUI on the device.

The weakness was shared 04/24/2023. The advisory is shared for download at zyxel.com. This vulnerability is handled as CVE-2023-27990 since 03/09/2023. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available. The MITRE ATT&CK project declares the attack technique as T1059.007.

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-2023-31715). Once again VulDB remains the best source for vulnerability data.

Productinfo

Type

Vendor

Name

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.0
VulDB Meta Temp Score: 4.0

VulDB Base Score: 2.4
VulDB Temp Score: 2.4
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 4.8
NVD Vector: 🔍

CNA Base Score: 4.8
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: Cross site scripting
CWE: CWE-79 / CWE-94 / 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

03/09/2023 🔍
04/24/2023 +45 days 🔍
04/24/2023 +0 days 🔍
02/25/2026 +1038 days 🔍

Sourcesinfo

Vendor: zyxel.com

Advisory: zyxel.com
Status: Confirmed

CVE: CVE-2023-27990 (🔍)
GCVE (CVE): GCVE-0-2023-27990
GCVE (VulDB): GCVE-100-227324
EUVD: 🔍

Entryinfo

Created: 04/24/2023 20:47
Updated: 02/25/2026 23:52
Changes: 04/24/2023 20:47 (48), 05/18/2023 14:13 (11), 12/01/2025 05:38 (16), 02/25/2026 23:52 (5)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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