Cyber Resilience

CVE-2023-31903

CriticalPublic PoC

Published: 17 May 2023

Published
17 May 2023
Modified
27 January 2025
KEV Added
Patch
CVSS Score v3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0201 84.1th percentile
Risk Priority 21 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2023-31903 is a critical-severity Unrestricted Upload of File with Dangerous Type (CWE-434) vulnerability in Freeguppy Guppy. Its CVSS base score is 9.8 (Critical).

Operationally, ranked in the top 15.9% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

Deeper analysis

GuppY CMS version 6.00.10 contains an unrestricted file upload vulnerability tracked as CVE-2023-31903 and assigned CWE-434. The flaw permits remote attackers to upload arbitrary PHP files to the application, which are then executed on the server. The issue carries a CVSS 3.1 base score of 9.8, reflecting network-accessible exploitation with no required credentials or user interaction and full impact on confidentiality, integrity, and availability.

Unauthenticated remote attackers can exploit the weakness by uploading a malicious PHP file through the affected upload functionality. Successful exploitation results in arbitrary code execution on the underlying server, enabling complete system compromise including data theft, persistence, or further lateral movement within the environment.

Public proof-of-concept exploits for the vulnerability have been published on GitHub and Exploit-DB. The EPSS score rose from lower values to a peak of 0.0809 before receding to its current level of 0.0201, indicating a period of increased exploitation interest after disclosure. No official patch or mitigation guidance appears in the available references.

EU & UK References

Vulnerability details

GuppY CMS 6.00.10 is vulnerable to Unrestricted File Upload which allows remote attackers to execute arbitrary code by uploading a php file.

CWE(s)

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

freeguppy
guppy
6.00.10

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

addresses: CWE-434

Requiring identifiable owners for portable devices reduces the attack surface for unrestricted uploads of dangerous file types via anonymous media.

addresses: CWE-434

Dangerous file uploads can be detonated in the chamber to determine malice before any production write or execution occurs.

addresses: CWE-434

Prevents unrestricted writing of arbitrary or malicious firmware by keeping hardware write-protect enabled except under tightly controlled manual procedures.

addresses: CWE-434

Scans files from external sources on download/open/execute, blocking unrestricted uploads of dangerous file types.

References