Arbitrary file upload in S9y Serendipity
CVE-2023-53933
Serendipity 2.4.0 contains a remote code execution vulnerability that allows authenticated attackers to upload malicious PHP files with .phar extension. Attackers can upload files with system command payloads to the media upload endpoint and execute arbitrary commands on the server.
Vulnerability class: Unrestricted File Upload
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.010 (61.9th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 62nd percentile — 61.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.010 · newest: 0.010 · change: +0.000
Affected products
- S9y Serendipity — versions 2.4.0
Weakness classification (CWE)
References
- www.exploit-db.com/exploits/51372 (Exploit, VDB Entry, Third Party Advisory, exploit)
- docs.s9y.org/ (Product, product)
- www.vulncheck.com/advisories/serendipity-authenticated-remote-code-execution-vi… (Exploit, Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2023-53933?
- CVE-2023-53933 is a high-severity vulnerability in S9y Serendipity, classified under Unrestricted Upload of File with Dangerous Type. CVSS score: 8.8/10. Published 2025-12-17.
- How severe is CVE-2023-53933?
- High severity. CVSS v3 base score is 8.8 out of 10.