OPNsense 18.7.x before 18.7.7 has Incorrect Access Control.

Incorrect access control in the WebUI in OPNsense before version 19.1.8, and pfsense before 2.4.4-p3 allows remote authenticated users to escalate privileges to administrator via a specially crafted request.

OPNsense 19.1 contains multiple cross-site scripting vulnerabilities in the diag_backup.php endpoint that allow attackers to inject malicious scripts through multiple parameters including GDrive_GDriveEmail, GDrive_GDriveFolderID, GDrive_GDriveBackupCount, Nextcloud_url, Nextcloud_user, Nextcloud_password, Nextcloud_password_encryption, and Nextcloud_backupdir. Attackers can submit POST requests with script payloads in these parameters to execute arbitrary JavaScript in the context of authenticated administrator sessions.

OPNsense 19.1 contains a stored cross-site scripting vulnerability in the system_advanced_sysctl.php endpoint that allows attackers to inject persistent malicious scripts via the tunable parameter. Attackers can submit POST requests with script payloads that are stored and executed in the context of authenticated user sessions when the page is viewed.

OPNsense 19.1 contains a reflected cross-site scripting vulnerability that allows attackers to inject malicious scripts by submitting crafted input through multiple parameters. Attackers can send POST requests to interfaces_vlan_edit.php with script payloads in the tag, descr, or vlanif parameters to execute arbitrary JavaScript in users' browsers.

OPNsense 19.1 contains a reflected cross-site scripting vulnerability that allows unauthenticated attackers to inject malicious scripts by exploiting insufficient input validation in the host parameter. Attackers can submit crafted POST requests to the diag_ping.php endpoint with script payloads in the host parameter to execute arbitrary JavaScript in users' browsers.

OPNsense 19.1 contains a reflected cross-site scripting vulnerability that allows unauthenticated attackers to inject malicious scripts by exploiting insufficient input validation in the host parameter. Attackers can submit crafted payloads through POST requests to diag_traceroute.php to execute arbitrary JavaScript in the context of a user's browser session.

OPNsense 19.1 contains a stored cross-site scripting vulnerability that allows authenticated attackers to inject malicious scripts by submitting crafted input to the category parameter. Attackers can send POST requests to firewall_rules_edit.php with script payloads in the category field to execute arbitrary JavaScript in the browsers of other users accessing firewall rule pages.

OPNsense 19.1 contains a reflected cross-site scripting vulnerability that allows attackers to inject malicious scripts by exploiting the passthrough_networks parameter in vpn_ipsec_settings.php. Attackers can craft POST requests with JavaScript payloads in the passthrough_networks parameter to execute arbitrary code in users' browsers.

OPNsense 19.1 contains a reflected cross-site scripting vulnerability that allows unauthenticated attackers to inject malicious scripts by submitting crafted input to the mailserver parameter. Attackers can send POST requests to the monit interface with JavaScript payloads in the mailserver parameter to execute arbitrary code in users' browsers.

OPNsense 19.1 contains a reflected cross-site scripting vulnerability that allows unauthenticated attackers to inject malicious scripts by submitting crafted payloads through the ignoreLogACL parameter. Attackers can send POST requests to the proxy endpoint with JavaScript code in the ignoreLogACL parameter to execute arbitrary scripts in users' browsers.

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.

An open redirect issue was discovered in OPNsense through 20.1.5. The redirect parameter "url" in login page was not filtered and can redirect user to any website.

A Cross-site scripting (XSS) vulnerability was discovered in OPNsense before 21.7.4 via the LDAP attribute return in the authentication tester.

DECISO OPNsense 23.1 does not impose rate limits for authentication, allowing attackers to perform a brute-force attack to bypass authentication.

A directory traversal vulnerability in the Captive Portal templates of OPNsense Community Edition before 23.7 and Business Edition before 23.4.2 allows attackers to execute arbitrary system commands as root via a crafted ZIP archive.

An open redirect in the Login page of OPNsense Community Edition before 23.7 and Business Edition before 23.4.2 allows attackers to redirect a victim user to an arbitrary web site via a crafted URL.

A Cross-Site Request Forgery (CSRF) in the System Halt API (/system/halt) of OPNsense Community Edition before 23.7 and Business Edition before 23.4.2 allows attackers to cause a Denial of Service (DoS) via a crafted GET request.

A reflected cross-site scripting (XSS) vulnerability in the component /ui/diagnostics/log/core/ of OPNsense Community Edition before 23.7 and Business Edition before 23.4.2 allows attackers to inject arbitrary JavaScript via the URL path.

A command injection vulnerability in the component diag_backup.php of OPNsense Community Edition before 23.7 and Business Edition before 23.4.2 allows attackers to execute arbitrary commands via a crafted backup configuration file.

A cross-site scripting (XSS) vulnerability in the act parameter of system_certmanager.php in OPNsense Community Edition before 23.7 and Business Edition before 23.4.2 allows attackers to execute arbitrary web scripts or HTML via a crafted payload.

OPNsense Community Edition before 23.7 and Business Edition before 23.4.2 was discovered to contain insecure permissions in the directory /tmp.

Insecure permissions in the configuration directory (/conf/) of OPNsense Community Edition before 23.7 and Business Edition before 23.4.2 allow attackers to access sensitive information (e.g., hashed root password) which could lead to privilege escalation.

Insecure permissions exist for configd.socket in OPNsense Community Edition before 23.7 and Business Edition before 23.4.2.

The Crash Reporter (crash_reporter.php) component of OPNsense Community Edition before 23.7 and Business Edition before 23.4.2 mishandles input sanitization.

/ui/cron/item/open in the Cron component of OPNsense Community Edition before 23.7 and Business Edition before 23.4.2 allows XSS via openAction in app/controllers/OPNsense/Cron/ItemController.php.

A command injection vulnerability in the component /api/cron/settings/setJob/ of OPNsense Community Edition before 23.7 and Business Edition before 23.4.2 allows attackers to execute arbitrary system commands.

OPNsense before 23.7.5 allows XSS via the index.php column_count parameter to the Lobby Dashboard.

OPNsense before 23.7.5 allows XSS via the index.php sequence parameter to the Lobby Dashboard.

OPNsense before 25.1.8 contains an authenticated command injection vulnerability in its Bridge Interface Edit endpoint (interfaces_bridge_edit.php). The span POST parameter is concatenated into a system-level command without proper sanitization or escaping, allowing an administrator to inject arbitrary shell operators and payloads. Successful exploitation results in remote code execution with the privileges of the web service (typically root), potentially leading to full system compromise or lateral movement. This vulnerability arises from inadequate input validation and improper handling of user-supplied data in backend command invocations.

OPNsense is a FreeBSD based firewall and routing platform. Prior to 26.1.4, multiple OPNsense MVC API endpoints perform state‑changing operations but are accessible via HTTP GET requests without CSRF protection. The framework CSRF validation in ApiControllerBase only applies to POST/PUT/DELETE methods, allowing authenticated GET requests to bypass CSRF verification. As a result, a malicious website can trigger privileged backend actions when visited by an authenticated user, causing unintended service reloads and configuration changes through configd. This results in an authenticated Cross‑Site Request Forgery vulnerability allowing unauthorized system state changes. This vulnerability is fixed in 26.1.4.