CVE-2021-47753

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.

CVSS v4.0

9.3 CRITICALCVSS: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

CVSS v3.1

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

EPSS

0.68% chance of exploitation in the next 30 days, 50th percentile

Published

2026-01-15

Updated

2026-04-07

Proof-of-concept exploits (1)

• https://www.exploit-db.com/exploits/50610

References

• CVE Record
• NVD entry

Related

• CVE-2021-47752
• CVE-2021-47754
• CVE-2021-47751
• CVE-2021-47755
• CVE-2021-47750
• CVE-2021-47756