CVE-2021-21260Network attack vector

Administrator takeover via unsanitized item description

Published Jan 22, 2021 · Updated Aug 3, 2024

Stored XSS in BigProf Software Online Invoicing System 4.0 allows remote authenticated users to take over an administrator account. The item-description rendering path in app/items_view.php returns stored field content without sanitization, allowing injected script to run in an administrator's browser. A low-privileged account can plant the payload, but an administrator must view the item; the script can extract a CSRF token and submit a password-change request.

CVSS severity7.6
High
EPSS probability0.60%
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 BigProf Software Online Invoicing System 4.0 allows remote authenticated users to take over an administrator account. The item-description rendering path in app/items_view.php returns stored field content without sanitization, allowing injected script to run in an administrator's browser. A low-privileged account can plant the payload, but an administrator must view the item; the script can extract a CSRF token and submit a password-change request.

The record

CVE
CVE-2021-21260
Published
Jan 22, 2021
Updated
Aug 3, 2024
Vendor
BigProf Software
Product
Online Invoicing System
Classifications
CWE-79, T1203
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 22, 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== 4.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

BigProf Software · Online Invoicing Systemversion== 4.0

Published CVSS scores

3.5NIST NVDAV:N/AC:M/Au:S/C:N/I:P/A:N
5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
7.6GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/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 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-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1203Exploitation for Client Execution

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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