CVE-2021-4309Network attack vector

Script execution via untrusted request path

Published Jan 8, 2023 · Updated Apr 9, 2025

Reflected XSS in 01-Scripts 01ACP allows remote authenticated users to inject script through a crafted request path. Affected PHP pages copy attacker-controlled $_SERVER['PHP_SELF'] into the $filename value used in page output instead of the path-only $_SERVER['SCRIPT_NAME']. Exploitation requires a user to open the crafted path, after which script executes in that user's browser with the application's origin.

CVSS severity3.5
Low
EPSS probability0.52%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Reflected XSS in 01-Scripts 01ACP allows remote authenticated users to inject script through a crafted request path. Affected PHP pages copy attacker-controlled $_SERVER['PHP_SELF'] into the $filename value used in page output instead of the path-only $_SERVER['SCRIPT_NAME']. Exploitation requires a user to open the crafted path, after which script executes in that user's browser with the application's origin.

The record

CVE
CVE-2021-4309
Published
Jan 8, 2023
Updated
Apr 9, 2025
Vendor
01-Scripts
Product
01ACP
Classifications
CWE-79, T1189
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 8, 2023CVE publishedPublication date reported by the CVE source.
  2. Apr 9, 2025Record 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=n/a

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

01-Scripts · 01ACPversion=n/a

Published CVSS scores

4.0VulDBAV:N/AC:L/Au:S/C:N/I:P/A:N
3.5VulDBCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N
6.1NIST NVDCVSS: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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1189Drive-by Compromise

Public exploit references

No public exploit references are available in this record.

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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