CVE-2019-25377 OPNsense 19.1 Reflected XSS via system_advanced_sysctl.php
Attackers can inject malicious scripts via the value parameter in system_advanced_sysctl.php, executing JavaScript in authenticated user sessions.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2019-25377?
CVE-2019-25377 is a medium-severity cross-site scripting vulnerability in OPNsense, published on 15 Feb 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Official 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.
Weakness: CWE-79
Which versions are affected by CVE-2019-25377?
It affects 1 product.
Products include Opnsense Opnsense.
How do I fix CVE-2019-25377?
No fix has been published for CVE-2019-25377 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2019-25377 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2019-25377 exists.
Other vulnerabilities in OPNsense
Sources
Also known as GHSA-hp2h-w474-f9g4.