CVE-2021-45808Public exploitNetwork attack vector

Authenticated arbitrary file upload via partial validation

Published Jan 19, 2022 · Updated Jul 9, 2026

Unrestricted file upload in JPress 4.2.0 allows remote authenticated users to write arbitrary files through the attachment interface. AttachmentController#upload saves every multipart file into the attachment directory but validates and deletes only the first array element. Default self-registration supplies the required account, and a crafted multi-file request leaves a disallowed second file stored server-side.

CVSS severity8.8
High
EPSS probability1.31%
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 JPress 4.2.0 allows remote authenticated users to write arbitrary files through the attachment interface. AttachmentController#upload saves every multipart file into the attachment directory but validates and deletes only the first array element. Default self-registration supplies the required account, and a crafted multi-file request leaves a disallowed second file stored server-side.

The record

CVE
CVE-2021-45808
Published
Jan 19, 2022
Updated
Jul 9, 2026
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-434, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 19, 2022CVE publishedPublication date reported by the CVE source.
  2. Jul 9, 2026Record 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 privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
6.5NIST NVDAV:N/AC:L/Au:S/C:P/I:P/A:P

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
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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