CVE-2023-5820Network attack vector

Unauthenticated arbitrary file upload via missing nonce validation

Published Oct 27, 2023 · Updated Feb 5, 2025

Cross-site request forgery in Thumbnail Slider With Lightbox 1.0 allows remote attackers to upload arbitrary files through a forged request. The addedit functionality accepts state-changing upload requests without correctly validating a WordPress nonce. Exploitation requires an authenticated site administrator to follow an attacker-controlled link, causing the administrator's browser to submit the upload.

CVSS severity9.6
Critical
EPSS probability0.32%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site request forgery in Thumbnail Slider With Lightbox 1.0 allows remote attackers to upload arbitrary files through a forged request. The addedit functionality accepts state-changing upload requests without correctly validating a WordPress nonce. Exploitation requires an authenticated site administrator to follow an attacker-controlled link, causing the administrator's browser to submit the upload.

The record

CVE
CVE-2023-5820
Published
Oct 27, 2023
Updated
Feb 5, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-352, T1204.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 27, 2023CVE publishedPublication date reported by the CVE source.
  2. Feb 5, 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?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.6Wordfence CNACVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
8.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
8.3Wordfence IntelligenceCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-352Cross-Site Request Forgery (CSRF)
T1204.001Malicious Link

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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