OPNsense 19.1 POST Request system_advanced_sysctl.php tunable cross site scripting

Summaryinfo

A vulnerability was found in OPNsense 19.1. It has been rated as problematic. This vulnerability affects unknown code of the file system_advanced_sysctl.php of the component POST Request Handler. This manipulation of the argument tunable causes cross site scripting. The identification of this vulnerability is CVE-2019-25369. It is possible to initiate the attack remotely. Furthermore, there is an exploit available.

Detailsinfo

A vulnerability was found in OPNsense 19.1. It has been declared as problematic. Affected by this vulnerability is an unknown function of the file system_advanced_sysctl.php of the component POST Request Handler. The manipulation of the argument tunable with an unknown input leads to a cross site scripting vulnerability. The CWE definition for the vulnerability is CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. As an impact it is known to affect integrity. The summary by CVE is:

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.

The weakness was shared by Ozer Goker as 46351. The advisory is shared at exploit-db.com. This vulnerability is known as CVE-2019-25369 since 02/15/2026. The exploitation appears to be easy. The attack can be launched remotely. It demands that the victim is doing some kind of user interaction. Technical details and also a public exploit are known. MITRE ATT&CK project uses the attack technique T1059.007 for this issue.

It is possible to download the exploit at exploit-db.com. It is declared as proof-of-concept. By approaching the search of inurl:system_advanced_sysctl.php it is possible to find vulnerable targets with Google Hacking.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the databases at Exploit-DB (46351) and EUVD (EUVD-2019-19426). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Name

• OPNsense

Version

• 19.1

CPE 2.3info

• 🔒

CPE 2.2info

• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Discussion