CVE-2021-43102Public exploitNetwork attack vector

Authenticated code execution via filename validation bypass

Published Mar 28, 2022 · Updated Aug 4, 2024

Unrestricted file upload in diyhi bbs 5.3 allows remote authenticated users to execute arbitrary code through an administrator upload. HelpManageAction.java accepts an application/octet-stream upload after GetType checks only file-header signatures and does not constrain the filename suffix. Administrator access is required; a crafted JSP filename passes this check and installs a web shell that executes code on the server.

CVSS severity7.2
High
EPSS probability1.63%
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 diyhi bbs 5.3 allows remote authenticated users to execute arbitrary code through an administrator upload. HelpManageAction.java accepts an application/octet-stream upload after GetType checks only file-header signatures and does not constrain the filename suffix. Administrator access is required; a crafted JSP filename passes this check and installs a web shell that executes code on the server.

The record

CVE
CVE-2021-43102
Published
Mar 28, 2022
Updated
Aug 4, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-434, T1505.003
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Mar 28, 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 privilegesadmin

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

6.5NIST NVDAV:N/AC:L/Au:S/C:P/I:P/A:P
7.2NIST NVDCVSS:3.1/AV:N/AC:L/PR:H/UI:N/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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-434Unrestricted Upload of File with Dangerous Type
T1505.003Web Shell

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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