Arbitrary file upload in Mfscripts Yetishare File Hosting Script

CVE-2021-47899

YetiShare File Hosting Script 5.1.0 contains a server-side request forgery vulnerability that allows attackers to read local system files through the remote file upload feature. Attackers can exploit the url parameter in the url_upload_handler endpoint to access sensitive files like /etc/passwd by using file:/// protocol.

Vulnerability class: Unrestricted File Upload

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.0 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.003 (19.7th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 20th percentile — 19.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2021-47899: held from 0.003 to 0.003.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2021-47899?
CVE-2021-47899 is a medium-severity vulnerability in Mfscripts Yetishare File Hosting Script, classified under Unrestricted Upload of File with Dangerous Type. CVSS score: 4.0/10. Published 2026-01-23.
How severe is CVE-2021-47899?
Medium severity. CVSS v3 base score is 4.0 out of 10.