CVE-2023-4496Public exploitNetwork attack vector

Browser script execution via unencoded chat recipient

Published Oct 4, 2023 · Updated Sep 5, 2024

Stored XSS in Easy Chat Server 3.1 and earlier allows remote attackers to execute script in another chat user's browser. The body2.ghp handler inserts the mtowho value into a JavaScript argument and the chat board's innerHTML without output encoding. Exploitation requires another chat user to render the poisoned entry; the script then runs in the service's browser origin and can read or modify content available to that user.

CVSS severity6.1
Medium
EPSS probability0.42%
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 Easy Chat Server 3.1 and earlier allows remote attackers to execute script in another chat user's browser. The body2.ghp handler inserts the mtowho value into a JavaScript argument and the chat board's innerHTML without output encoding. Exploitation requires another chat user to render the poisoned entry; the script then runs in the service's browser origin and can read or modify content available to that user.

The record

CVE
CVE-2023-4496
Published
Oct 4, 2023
Updated
Sep 5, 2024
Vendor
EFS Software, Inc.
Product
Easy Chat Server
Classifications
CWE-79, CAPEC-63, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 4, 2023CVE publishedPublication date reported by the CVE source.
  2. Sep 5, 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=0 <=3.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

EFS Software, Inc. · Easy Chat Serverversion=0 <=3.1

Published CVSS scores

6.1Spanish National Cybersecurity Institute, S.A. (INCIBE)CVSS: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')
CAPEC-63Cross-Site Scripting (XSS)
T1203Exploitation for Client Execution

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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