Remote Code Execution Vulnerability in OpenCATS by OpenCATS
CVE-2021-47936

9.3CRITICAL

Key Information:

Vendor

Opencats

Status
Opencats
Vendor
CVE Published:
10 May 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2021-47936?

OpenCATS version 0.9.4 is susceptible to a remote code execution vulnerability that enables unauthenticated attackers to execute arbitrary commands on the server. This exploit occurs when malicious PHP files, disguised as resume attachments, are uploaded through the careers job application endpoint. Attackers can leverage this vulnerability to submit POST requests to the uploaded files in the upload directory, thereby executing undesirable commands and potentially compromising the entire system.

Affected Version(s)

OpenCATS 0 <= 0.9.4

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2021-47936 - Proof of Concept

References

https://www.exploit-db.com/exploits/50585
exploit
https://www.opencats.org/
product
https://github.com/opencats/OpenCATS
product

CVSS V4

Score:
9.3
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

Nicholas Ferreira - https://github.com/Nickguitar
.