CVE-2025-21624
Oxygenz Clipbucket 5.3 – 5.5.1-239
Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2025-21624 is a critical-severity Unrestricted Upload of File with Dangerous Type (CWE-434) vulnerability in Oxygenz Clipbucket. Its CVSS base score is 9.8 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 34% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified map to SI-3 (Malicious Code Protection) and CM-7 (Least Functionality) — see the control section below for these in your framework.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
ClipBucket V5 is an open-source PHP-based video hosting platform. Prior to version 5.5.1-239, it contained an unrestricted file upload flaw in the Manage Playlist feature that handles playlist cover images. The absence of server-side validation allowed an uploaded file to retain a .php extension instead of being restricted to an image format, enabling storage and later execution of arbitrary code such as a webshell. The issue affects both administrative and ordinary user interfaces.
An unauthenticated remote attacker can exploit the flaw over the network by submitting a crafted playlist cover upload containing PHP code. Successful exploitation grants the ability to execute arbitrary commands on the underlying server, resulting in full confidentiality, integrity, and availability impact as reflected by the CVSS 9.8 score.
The vulnerability is addressed in release 5.5.1-239; the corresponding commit and GitHub Security Advisory GHSA-98vm-2xqm-xrcc document the fix. The current EPSS of 0.3291 has remained flat at its recorded peak, indicating sustained but not newly emerging exploitation interest.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-2576
Vulnerability Data
ClipBucket V5 provides open source video hosting with PHP. Prior to 5.5.1 - 239, a file upload vulnerability exists in the Manage Playlist functionality of the application, specifically surrounding the uploading of playlist cover images. Without proper checks, an attacker…
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can upload a PHP script file instead of an image file, thus allowing a webshell or other malicious files to be stored and executed on the server. This attack vector exists in both the admin area and low-level user area. This vulnerability is fixed in 5.5.1 - 239.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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V5.1.1
Mitigating Controls (NIST 800-53 r5) AI
Malicious-code protection at entry points blocks dangerous file types from being accepted and executed.
Least functionality restricts the file types and automatic processing capabilities the system will accept.
Mobile-code controls define, authorize, and block unacceptable uploaded code before automatic processing occurs.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Restricting execution of unauthorized software directly blocks dangerous uploaded files from running.
Hardened configuration baselines can enforce allowed file types and processing rules.
Secure development practices include input validation and file-type restrictions that prevent this weakness.
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Configuration and acceptance testing verify that file-upload handling enforces allowed types and does not permit dangerous content to be stored or executed.
Secure-coding guidelines and security testing explicitly address restrictions on allowed file types and upload handling, reducing the risk that dangerous file uploads are accepted without validation.
Mandated testing for malicious content and known vulnerabilities reduces the likelihood that an outsourced component will contain or accept dangerous file types that could later be uploaded or executed.
Application allow-listing and pre-use scanning of received files directly blocks the introduction of executable content that has not been vetted, eliminating the primary vector for unrestricted dangerous file uploads.