CVE-2023-53921
Published: 17 December 2025
Summary
CVE-2023-53921 is a high-severity Unrestricted Upload of File with Dangerous Type (CWE-434) vulnerability in Sitemagic Sitemagic Cms. Its CVSS base score is 8.7 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked in the top 48.2% 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 CM-6 (Configuration Settings) and SI-10 (Information Input Validation).
Deeper analysis
SitemagicCMS version 4.4.3 is affected by CVE-2023-53921, a remote code execution vulnerability stemming from CWE-434 (Unrestricted Upload of File with Dangerous Type). The flaw enables attackers to upload malicious PHP files, specifically .phar files containing system command execution payloads, to the files/images directory of the web application. This critical issue 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), highlighting its severity due to high confidentiality, integrity, and availability impacts.
Unauthenticated remote attackers can exploit this vulnerability over the network with low complexity and no user interaction required. By uploading a crafted .phar file to the vulnerable directory, attackers gain the ability to compromise the web application and execute arbitrary system commands on the underlying server, potentially leading to full server takeover.
Advisories from Vulncheck document the unrestricted file upload leading to remote code execution, while a public proof-of-concept exploit is available on Exploit-DB (ID 51464). The vendor's download page at sitemagic.org provides access to software updates, which security practitioners should review for patches addressing this issue.
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2023-60210
Vulnerability details
SitemagicCMS 4.4.3 contains a remote code execution vulnerability that allows attackers to upload malicious PHP files to the files/images directory. Attackers can upload a .phar file with system command execution payload to compromise the web application and execute arbitrary system…
more
commands.
- CWE(s)
Related Threats
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
The vulnerability is an unauthenticated remote code execution via unrestricted upload of dangerous files (.phar with command execution payloads) in a public-facing web application, directly enabling T1190: Exploit Public-Facing Application.
CVEs Like This One
Affected Assets
Mitigating Controls
Mitigating Controls (NIST 800-53 r5) AI
Directly remediates the specific unrestricted file upload flaw in SitemagicCMS by applying vendor-provided patches to prevent malicious .phar uploads.
Validates file uploads to block dangerous types like .phar containing PHP code execution payloads, addressing the core CWE-434 vulnerability.
Enforces secure configuration settings on the web server to disable script execution in the files/images directory, preventing RCE even if malicious files are uploaded.