CVE-2021-40909Public exploitNetwork attack vector

Stored XSS via unsanitized ajax_crud fields

Published Jan 24, 2022 · Updated Aug 4, 2024

Cross-site scripting in sourcecodester PHP CRUD Ajax DataTables Tutorial v1 allows remote attackers to execute code via /ajax_crud fields. The ajax_crud handler stores first_name, last_name, and email values without output encoding or prepared SQL statements, allowing crafted markup and SQL metacharacters to persist in MySQL and execute when records are rendered. Remote attackers need only submit the vulnerable fields; exploitation depends on a user viewing the stored record, and the resulting impact can include script execution, data compromise, or service interruption.

CVSS severity9.6
Critical
EPSS probability2.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in sourcecodester PHP CRUD Ajax DataTables Tutorial v1 allows remote attackers to execute code via /ajax_crud fields. The ajax_crud handler stores first_name, last_name, and email values without output encoding or prepared SQL statements, allowing crafted markup and SQL metacharacters to persist in MySQL and execute when records are rendered. Remote attackers need only submit the vulnerable fields; exploitation depends on a user viewing the stored record, and the resulting impact can include script execution, data compromise, or service interruption.

The record

CVE
CVE-2021-40909
Published
Jan 24, 2022
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-89, CWE-79, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 24, 2022CVE 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 privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.8NVDAV:N/AC:M/Au:N/C:P/I:P/A:P
9.6NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-89Improper Neutralization of Special Elements used in an SQL Command ('SQL Injection')
CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1189Drive-by Compromise

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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