Cross-Site Scripting in CMSimple by CMSimple
CVE-2021-47733

5.1MEDIUM

Key Information:

Vendor

Cmsimple

Status
Cmsimple
Vendor
CVE Published:
23 December 2025

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2021-47733?

CMSimple version 5.4 is susceptible to a cross-site scripting vulnerability that enables attackers to bypass input filtering mechanisms. By using HTML to Unicode encoding, malicious actors can inject harmful scripts, allowing them to execute arbitrary JavaScript when users interact with specific elements, such as delete buttons. This vulnerability poses significant risks to user security and data integrity.

Affected Version(s)

CMSimple <=5.4

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-2021-47733 - Proof of Concept

References

https://www.exploit-db.com/exploits/50612
exploit
https://www.cmsimple.org/en/
product
https://www.vulncheck.com/advisories/cmsimple-cross-site-...
third-party-advisory

CVSS V4

Score:
5.1
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

heinjame
JSON
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CVE-2021-47733 : Cross-Site Scripting in CMSimple by CMSimple