What is CVE-2020-20287?

CVE-2020-20287 is a critical-severity vulnerability in Yccms, classified under Unrestricted Upload of File with Dangerous Type. CVSS score: 9.8/10. Published 2021-02-01.

How severe is CVE-2020-20287?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Arbitrary file upload in Yccms

CVE-2020-20287

Unrestricted file upload vulnerability in the yccms 3.3 project. The xhUp function's improper judgment of the request parameters, triggers remote code execution.

Vulnerability class: Unrestricted File Upload

Published 2021-02-01 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.028 (86.1th percentile), scored 2026-10-03.

Low probability of exploitation in the next 30 days, but still tracked. 86th percentile — 86.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.028 · newest: 0.028 · change: 0.000

Affected products

Yccms — versions 3.3

Weakness classification (CWE)

CWE-434 — Unrestricted Upload of File with Dangerous Type

References

www.yccms.net/ (URL Repurposed, Broken Link)
blog.jiguang.xyz/posts/remote-code-execution-via-upload-image/ (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2020-20287?: CVE-2020-20287 is a critical-severity vulnerability in Yccms, classified under Unrestricted Upload of File with Dangerous Type. CVSS score: 9.8/10. Published 2021-02-01.
How severe is CVE-2020-20287?: Critical severity. CVSS v3 base score is 9.8 out of 10.