CVE-2021-23562Network attack vector

Script execution via unencoded filename metadata

Published Dec 3, 2021 · Updated Sep 16, 2024

Cross-site scripting in Tiny Technologies Plupload before 2.3.9 allows remote attackers to run JavaScript through a crafted filename. The jQuery UI widget substitutes file metadata into generated markup without XML-encoding the default placeholder value, so HTML-significant filename characters become executable page content. Exploitation requires a user to select the attacker-controlled file for upload; the resulting script runs in the embedding application's browser context.

CVSS severity4.2
Medium
EPSS probability0.99%
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 Tiny Technologies Plupload before 2.3.9 allows remote attackers to run JavaScript through a crafted filename. The jQuery UI widget substitutes file metadata into generated markup without XML-encoding the default placeholder value, so HTML-significant filename characters become executable page content. Exploitation requires a user to select the attacker-controlled file for upload; the resulting script runs in the embedding application's browser context.

The record

CVE
CVE-2021-23562
Published
Dec 3, 2021
Updated
Sep 16, 2024
Vendor
Tiny Technologies
Product
Plupload
Classifications
CWE-434, CWE-75, T1204.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Dec 3, 2021CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 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=unspecified <2.3.9

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Tiny Technologies · Pluploadversion=unspecified <2.3.9

Published CVSS scores

4.2SnykCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:N
8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/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 exploitUnconfirmed

Weakness, pattern, technique

CWE-434Unrestricted Upload of File with Dangerous Type
CWE-75Failure to Sanitize Special Elements into a Different Plane (Special Element Injection)
T1204.002Malicious File

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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