CVE-2025-3830Public exploitNetwork attack vector

Stored script execution via unchecked upload extension

Published Apr 20, 2025 · Updated Apr 21, 2025

Unrestricted file upload in KuangStudy KuangSimpleBBS 1.0 allows remote authenticated users to store arbitrary files on the server. QuestionController.fileUpload retains the submitted filename extension, appends it to a UUID, and calls transferTo without validating the extension. A valid session is required; uploaded active content becomes web-accessible, enabling stored script execution in a visitor's browser.

CVSS severity5.3
Medium
EPSS probability0.50%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Unrestricted file upload in KuangStudy KuangSimpleBBS 1.0 allows remote authenticated users to store arbitrary files on the server. QuestionController.fileUpload retains the submitted filename extension, appends it to a UUID, and calls transferTo without validating the extension. A valid session is required; uploaded active content becomes web-accessible, enabling stored script execution in a visitor's browser.

The record

CVE
CVE-2025-3830
Published
Apr 20, 2025
Updated
Apr 21, 2025
Vendor
KuangStudy
Product
KuangSimpleBBS
Classifications
CWE-434, CWE-284, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 20, 2025CVE publishedPublication date reported by the CVE source.
  2. Apr 21, 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=1.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

KuangStudy · KuangSimpleBBSversion=1.0

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
6.5VulDBAV:N/AC:L/Au:S/C:P/I:P/A:P
5.3VulDBCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N
6.3VulDBCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L

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 exploitPublished

Weakness, pattern, technique

CWE-434Unrestricted Upload of File with Dangerous Type
CWE-284Improper Access Control
T1190Exploit Public-Facing Application

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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