Reflected Cross-Site Scripting Vulnerability in OPNsense Firewall by Deciso
CVE-2019-25377

4.8MEDIUM

Key Information:

Vendor

Opnsense

Status
Opnsense
Vendor
CVE Published:
15 February 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2019-25377?

The OPNsense firewall version 19.1 is affected by a reflected cross-site scripting vulnerability that occurs in the system_advanced_sysctl.php endpoint. This vulnerability allows attackers to inject and execute malicious scripts by manipulating the value parameter within POST requests. If successfully exploited, this could lead to unauthorized actions being executed in the context of authenticated user sessions, potentially compromising the security of user data and the integrity of the system.

Affected Version(s)

OPNsense 19.1

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-2019-25377 - Proof of Concept

References

https://www.exploit-db.com/exploits/46351
exploit
https://opnsense.org
product
https://forum.opnsense.org/index.php?topic=11469.0
patch

CVSS V4

Score:
4.8
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
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

Ozer Goker
.