How to fix CVE-2019-25377?

Within 30 days: Identify affected systems and apply vendor patches as part of regular patch cycle. Verify Content-Security-Policy and output encoding.

Is PHP affected by CVE-2019-25377?

Organizations using OPNsense 19.1 should be aware of moderate risk from CVE-2019-25377, a cross-site scripting vulnerability rated CVSS 5.4. Attackers could inject scripts to steal sessions or perform actions as authenticated users. Proof-of-concept code is publicly available.

CVE-2019-25377

MEDIUM

2026-02-15 [email protected]

5.4

CVSS 3.1

CVSS Vector

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

Low

Availability

None

Lifecycle Timeline

Analysis Generated

Mar 12, 2026 - 21:54 vuln.today

PoC Detected

Feb 18, 2026 - 19:08 vuln.today

Public exploit code

CVE Published

Feb 15, 2026 - 14:16 nvd

MEDIUM 5.4

Description

OPNsense 19.1 contains a reflected cross-site scripting vulnerability in the system_advanced_sysctl.php endpoint that allows attackers to inject malicious scripts via the value parameter. Attackers can craft POST requests with script payloads in the value parameter to execute JavaScript in the context of authenticated user sessions.

Analysis

Technical Context

Classified as CWE-79 (Cross-site Scripting (XSS)). Affects the system_advanced_sysctl.php component of Opnsense. OPNsense 19.1 contains a reflected cross-site scripting vulnerability in the system_advanced_sysctl.php endpoint that allows attackers to inject malicious scripts via the value parameter. Attackers can craft POST requests with script payloads in the value parameter to execute JavaScript in the context of authenticated user sessions.

Affected Products

Vendor: Opnsense. Product: Opnsense. Versions: up to 19.1. Component: system_advanced_sysctl.php.

Remediation

Monitor vendor advisories for a patch. Implement output encoding and Content Security Policy headers. Restrict network access to the affected service where possible.

Priority Score

Low Medium High Critical

KEV: 0

EPSS: +0.0

CVSS: +27

POC: +20

CVE-2019-25377 vulnerability details – vuln.today

Back

CVE-2019-25377

CVSS Vector

Lifecycle Timeline

Tags

Description

Analysis

Technical Context

Affected Products

Remediation

Priority Score

Share

CVE-2019-25377

CVSS Vector

Lifecycle Timeline

Tags

Description

Analysis

Technical Context

Affected Products

Remediation

Priority Score

Share

External POC / Exploit Code