CVE-2023-45889Public exploitNetwork attack vector

Universal script injection via incomplete domain validation

Published Jan 23, 2024 · Updated May 30, 2025

Universal cross-site scripting in ClassLink OneClick Extension 10.8 and earlier allows remote attackers to inject JavaScript into any webpage. The extension applies its regular-expression check for ClassLink-controlled URLs inconsistently, allowing an attacker-controlled domain to trigger privileged page injection. Exploitation requires a user with the extension installed to visit a crafted website; the injected script can read or alter content in other pages.

CVSS severity6.1
Medium
EPSS probability0.45%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Universal cross-site scripting in ClassLink OneClick Extension 10.8 and earlier allows remote attackers to inject JavaScript into any webpage. The extension applies its regular-expression check for ClassLink-controlled URLs inconsistently, allowing an attacker-controlled domain to trigger privileged page injection. Exploitation requires a user with the extension installed to visit a crafted website; the injected script can read or alter content in other pages.

The record

CVE
CVE-2023-45889
Published
Jan 23, 2024
Updated
May 30, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-79, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 23, 2024CVE publishedPublication date reported by the CVE source.
  2. May 30, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

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
6.1CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

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 exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1189Drive-by Compromise

Public exploit references

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

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo