CVE-2021-4050Public exploitNetwork attack vector

Stored XSS via unsanitized SVG avatar upload

Published Dec 8, 2021 · Updated Aug 3, 2024

Stored XSS in LiveHelperChat Live Helper Chat before 2.0 allows remote authenticated users to run script through an SVG avatar upload. The account-data upload handlers save SVG avatars without sanitizing active content, leaving browser-executable markup in the stored file. An attacker needs access to upload an account avatar, and a user must view the resulting SVG; script then runs in that viewer's browser context.

CVSS severity6.1
Medium
EPSS probability0.85%
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 LiveHelperChat Live Helper Chat before 2.0 allows remote authenticated users to run script through an SVG avatar upload. The account-data upload handlers save SVG avatars without sanitizing active content, leaving browser-executable markup in the stored file. An attacker needs access to upload an account avatar, and a user must view the resulting SVG; script then runs in that viewer's browser context.

The record

CVE
CVE-2021-4050
Published
Dec 8, 2021
Updated
Aug 3, 2024
Vendor
LiveHelperChat
Product
Live Helper Chat
Classifications
CWE-79, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 8, 2021CVE 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=unspecified <2.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

LiveHelperChat · Live Helper Chatversion=unspecified <2.0

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
6.1@huntrdev CNACVSS:3.0/AV:N/AC:L/PR:H/UI:R/S:U/C:H/I:H/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

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

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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