CVE-2023-53871
Published: 15 December 2025
Summary
CVE-2023-53871 is a medium-severity Unrestricted Upload of File with Dangerous Type (CWE-434) vulnerability in Soosyze Soosyze. Its CVSS base score is 6.9 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 36.6% 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 are NIST 800-53 SI-10 (Information Input Validation) and SI-3 (Malicious Code Protection).
Deeper analysis
CVE-2023-53871 is a file upload vulnerability in Soosyze 2.0.0, a content management system. The flaw allows attackers to upload arbitrary HTML files containing embedded PHP code due to a broken file upload mechanism. Exploitation can also disclose sensitive file paths and enable execution of malicious PHP scripts on the server. It carries a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H) and maps to CWE-434 (Unrestricted Upload of File with Dangerous Type).
Unauthenticated remote attackers can exploit this vulnerability over the network with low complexity and no user interaction required. Successful attacks achieve high impacts across confidentiality, integrity, and availability, primarily by executing arbitrary PHP code for potential remote code execution and revealing server file paths.
Advisories, including one from VulnCheck detailing the unrestricted file upload via broken upload logic, provide further technical analysis. An exploit is publicly available on Exploit-DB (ID 51718). Practitioners should review the official Soosyze GitHub repository and website for any patches or remediation guidance.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2025-203433
Vulnerability details
Soosyze 2.0.0 contains a file upload vulnerability that allows attackers to upload arbitrary HTML files with embedded PHP code to the application. Attackers can exploit the broken file upload mechanism to potentially view sensitive file paths and execute malicious PHP…
more
scripts on the server.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Unrestricted file upload in public-facing CMS enables unauthenticated RCE via PHP web shells (T1190, T1100).
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly addresses the unrestricted file upload vulnerability by requiring validation of uploaded files to block dangerous types like HTML with embedded PHP code.
Prevents exploitation by restricting file upload inputs to only safe types and formats, mitigating uploads of executable HTML/PHP files.
Mitigates malicious PHP script execution from uploaded files by scanning for and blocking malicious code at system entry points.