CVE-2021-38143Public exploitNetwork attack vector

Administrator session theft via stored customer names

Published Aug 31, 2021 · Updated Aug 4, 2024

Stored XSS in Form Tools 3.0.20 and earlier allows remote authenticated users to steal an administrator's session cookie. Customer-editable first-name and last-name fields store script payloads without neutralizing them before the administrator client list renders the values. A customer account and an administrator viewing the client list are required, and the injected script can extract the administrator's PHPSESSID cookie.

CVSS severity6.1
Medium
EPSS probability1.35%
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 Form Tools 3.0.20 and earlier allows remote authenticated users to steal an administrator's session cookie. Customer-editable first-name and last-name fields store script payloads without neutralizing them before the administrator client list renders the values. A customer account and an administrator viewing the client list are required, and the injected script can extract the administrator's PHPSESSID cookie.

The record

CVE
CVE-2021-38143
Published
Aug 31, 2021
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-79, T1539
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 31, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.1NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
4.3NIST NVDAV:N/AC:M/Au:N/C:N/I:P/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.

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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 exploitPublished

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1539Steal Web Session Cookie

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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