CVE-2023-31903Public exploitNetwork attack vector

Code execution via unrestricted PHP upload

Published May 17, 2023 · Updated Jan 27, 2025

Unrestricted file upload in GuppY CMS 6.00.10 allows remote attackers to execute arbitrary code by uploading a PHP file. The upload handler at guppy/admin/admin.php accepts a PHP file and places it under guppy/file, where a direct request executes its contents. The published exploit authenticates as an administrator before upload, although the published CVSS assessments list no required privileges.

CVSS severity9.8
Critical
EPSS probability2.08%
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 GuppY CMS 6.00.10 allows remote attackers to execute arbitrary code by uploading a PHP file. The upload handler at guppy/admin/admin.php accepts a PHP file and places it under guppy/file, where a direct request executes its contents. The published exploit authenticates as an administrator before upload, although the published CVSS assessments list no required privileges.

The record

CVE
CVE-2023-31903
Published
May 17, 2023
Updated
Jan 27, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-434, T1505.003
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 17, 2023CVE publishedPublication date reported by the CVE source.
  2. Jan 27, 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

9.8CISA-ADPCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/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
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-434Unrestricted Upload of File with Dangerous Type
T1505.003Server Software Component: Web 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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