CVE-2020-23054Network attack vector

Stored XSS via unsanitized user-agent input

Published Oct 22, 2021 · Updated Aug 4, 2024

NSK User Agent String Switcher Service v0.3.5 allows remote attackers to execute arbitrary web scripts or HTML through a crafted user-agent payload. The user-agent input field accepts markup that is rendered as web content without adequate neutralization, enabling cross-site scripting in a browser context. Exploitation requires a victim to process the crafted value; the documented impact is script execution with no reported server-side compromise.

CVSS severity6.1
Medium
EPSS probability0.74%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

NSK User Agent String Switcher Service v0.3.5 allows remote attackers to execute arbitrary web scripts or HTML through a crafted user-agent payload. The user-agent input field accepts markup that is rendered as web content without adequate neutralization, enabling cross-site scripting in a browser context. Exploitation requires a victim to process the crafted value; the documented impact is script execution with no reported server-side compromise.

The record

CVE
CVE-2020-23054
Published
Oct 22, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-79
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 22, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.1NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
4.3NVDAV:N/AC:M/Au:N/C:N/I:P/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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