Cyber Resilience

CVE-2025-23918

Critical

Published: 22 January 2025

Published
22 January 2025
Modified
23 April 2026
KEV Added
—
Patch
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CVSS Score v3.1 9.9 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS Score 0.0035 57.9th percentile
Risk Priority 20 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2025-23918 is a critical-severity Unrestricted Upload of File with Dangerous Type (CWE-434) vulnerability. Its CVSS base score is 9.9 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 42.1% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-2 (Flaw Remediation).

Deeper analysis

CVE-2025-23918 is an Unrestricted Upload of File with Dangerous Type vulnerability (CWE-434) in the Smallerik File Browser WordPress plugin developed by Enrico Sandoli. The flaw affects all versions from n/a through 1.1 and enables attackers to upload web shells directly to the web server. It carries a CVSS v3.1 base score of 9.9 (AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H), marking it as critically severe due to its network accessibility, low attack complexity, and potential for high-impact compromise across confidentiality, integrity, and availability.

Low-privileged users, such as authenticated WordPress contributors (PR:L), can exploit this vulnerability remotely over the network without requiring user interaction. By uploading malicious files like web shells, attackers achieve scope change (S:C) and full control over the server, enabling arbitrary code execution, data exfiltration, or further persistence.

Patchstack advisories document this as an arbitrary file upload vulnerability specifically in Smallerik File Browser plugin version 1.1 for WordPress, providing details on the issue for mitigation guidance.

EU & UK References

Vulnerability details

Unrestricted Upload of File with Dangerous Type vulnerability in Enrico Sandoli Smallerik File Browser smallerik-file-browser allows Upload a Web Shell to a Web Server.This issue affects Smallerik File Browser: from n/a through <= 1.1.

CWE(s)
CWE-434

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1505.003 Web Shell Persistence
Adversaries may backdoor web servers with web shells to establish persistent access to systems.
attack.mitre.org →
Why these techniques?

The vulnerability allows unrestricted upload of dangerous files (web shells) in a public-facing WordPress plugin, directly enabling exploitation of public-facing applications (T1190) and deployment of web shells (T1100) for code execution and persistence.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

CVEs Like This One

CVE-2025-46384Shared CWE-434
CVE-2025-13516Shared CWE-434
CVE-2024-13011Shared CWE-434
CVE-2025-8323Shared CWE-434
CVE-2025-21624Shared CWE-434
CVE-2026-35164Shared CWE-434
CVE-2026-2097Shared CWE-434
CVE-2025-12154Shared CWE-434
CVE-2026-42748Shared CWE-434
CVE-2025-32957Shared CWE-434

Affected Assets

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SI-10 Information Input Validation good match
prevent

Directly prevents unrestricted upload of dangerous file types like web shells by implementing validation mechanisms at file upload input points in the Smallerik File Browser plugin.

SI-2 Flaw Remediation good match
prevent

Requires timely identification, reporting, and patching of flaws like CVE-2025-23918 in vulnerable WordPress plugins to eliminate the unrestricted file upload vulnerability.

SI-9 Information Input Restrictions good match
prevent

Enforces restrictions on allowable file types and formats at upload points, blocking dangerous web shell uploads in the Smallerik File Browser.

References