CVE-2021-24491Public exploitNetwork attack vector

Arbitrary file upload and deletion via CSRF

Published Sep 13, 2021 · Updated Aug 3, 2024

CSRF in Vievern Fileviewer 2.2 and earlier allows remote attackers to upload or delete arbitrary files through an administrator's browser. The wp-admin Fileviewer handler accepts upload and deletion requests without a CSRF token check, treating forged requests as administrator actions. Exploitation requires a logged-in administrator to open attacker-controlled content; uploaded PHP files can execute on the WordPress host.

CVSS severity8.8
High
EPSS probability0.71%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

CSRF in Vievern Fileviewer 2.2 and earlier allows remote attackers to upload or delete arbitrary files through an administrator's browser. The wp-admin Fileviewer handler accepts upload and deletion requests without a CSRF token check, treating forged requests as administrator actions. Exploitation requires a logged-in administrator to open attacker-controlled content; uploaded PHP files can execute on the WordPress host.

The record

CVE
CVE-2021-24491
Published
Sep 13, 2021
Updated
Aug 3, 2024
Vendor
Vievern
Product
Fileviewer
Classifications
CWE-352, T1189
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 13, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 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=2.2 <=2.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Vievern · Fileviewerversion=2.2 <=2.2

Published CVSS scores

8.8WordfenceCVSS: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.

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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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-352Cross-Site Request Forgery (CSRF)
T1189Drive-by Compromise

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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