CVE-2021-4282Network attack vector

Stored XSS via unescaped settings values

Published Dec 27, 2022 · Updated Aug 3, 2024

Stored cross-site scripting in FreePBX Voicemail before 14.0.6.25 allows remote attackers to execute script through crafted settings. page.voicemail.php passes raw request data into settings updates, while views/ssettings.php renders saved number and text values into HTML attributes without encoding. Exploitation requires the ability to save a crafted setting and a second user to load the affected administration view, where the script runs in that user's browser.

CVSS severity3.5
Low
EPSS probability0.52%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored cross-site scripting in FreePBX Voicemail before 14.0.6.25 allows remote attackers to execute script through crafted settings. page.voicemail.php passes raw request data into settings updates, while views/ssettings.php renders saved number and text values into HTML attributes without encoding. Exploitation requires the ability to save a crafted setting and a second user to load the affected administration view, where the script runs in that user's browser.

The record

CVE
CVE-2021-4282
Published
Dec 27, 2022
Updated
Aug 3, 2024
Vendor
FreePBX
Product
FreePBX Voicemail
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
Unavailable

Timeline

How it unfolded

  1. Dec 27, 2022CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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?

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

  1. Affected versionversion=n/a

What conditions does exploitation require?

Attack vectornetwork
Required privilegesUnavailable in this record.

What is affected?

FreePBX · FreePBX Voicemailversion=n/a

Published CVSS scores

3.5VulDBCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N
6.1NIST NVDCVSS: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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
PrivilegesUnavailable
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1059.007Command and Scripting Interpreter: JavaScript/JScript

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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