CVE-2021-4074Network attack vector

Subscriber-level stored XSS via unchecked URL setting

Published Jan 18, 2022 · Updated Feb 14, 2025

Stored XSS in Global Programming WHMCS Bridge 6.1 and earlier allows remote authenticated users to inject scripts through plugin settings. The cc_whmcs_bridge_add_admin function accepts cc_whmcs_bridge_url without an authorization check or output-safe neutralization and stores the value. Subscriber-level access is sufficient; the stored payload executes when the affected setting is subsequently rendered in a browser.

CVSS severity6.4
Medium
EPSS probability0.56%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in Global Programming WHMCS Bridge 6.1 and earlier allows remote authenticated users to inject scripts through plugin settings. The cc_whmcs_bridge_add_admin function accepts cc_whmcs_bridge_url without an authorization check or output-safe neutralization and stores the value. Subscriber-level access is sufficient; the stored payload executes when the affected setting is subsequently rendered in a browser.

The record

CVE
CVE-2021-4074
Published
Jan 18, 2022
Updated
Feb 14, 2025
Vendor
Global Programming
Product
WHMCS Bridge
Classifications
CWE-862, CWE-79, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 18, 2022CVE publishedPublication date reported by the CVE source.
  2. Feb 14, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=6.1 <=6.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Global Programming · WHMCS Bridgeversion=6.1 <=6.1

Published CVSS scores

6.4WordfenceCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N
5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-862Missing Authorization
CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1190Exploit Public-Facing Application

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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