CVE-2021-47753

Name: CVE-2021-47753
Creator: NVD / NIST
Published: 2026-01-15T16:16:06.003+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.3/10EPSS 0.67%

Last modified Jun 17, 2026

CVE-2021-47753 is a critical-severity vulnerability rated 9.3/10 on the CVSS scale. phpKF CMS 3.00 Beta y6 contains an unauthenticated file upload vulnerability that allows remote attackers to execute arbitrary code by bypassing file extension checks. Attackers can upload a PHP file disguised as a PNG, rename it, and execute system commands through a crafted web shell parameter.. EPSS estimates a 0.67% chance of exploitation in the next 30 days.

Description

phpKF CMS 3.00 Beta y6 contains an unauthenticated file upload vulnerability that allows remote attackers to execute arbitrary code by bypassing file extension checks. Attackers can upload a PHP file disguised as a PNG, rename it, and execute system commands through a crafted web shell parameter.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS 4.0

9.3/10

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS Probability

0.67%

47.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-434

Affected Software

Vendor	Product	Versions	Update
Phpkf	Cms	3.00	Beta Y6

References

https://www.exploit-db.com/exploits/50610Exploit, Third Party Advisory
https://www.phpkf.com/Product
https://www.phpkf.com/indirme.phpProduct
https://www.exploit-db.com/exploits/50610Exploit, Third Party Advisory

Timeline

Published: Jan 15, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2021-47753?

How severe is CVE-2021-47753?

CVE-2021-47753 has a CVSS score of 9.3/10 (CRITICAL severity). The EPSS model estimates a 0.67% probability of exploitation in the next 30 days.

How do I fix CVE-2021-47753?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-47753?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST