SB2026050564 - Multiple vulnerabilities in OPNsense

Description

This security bulletin contains information about 2 vulnerabilities.

1) Improper Neutralization of Argument Delimiters in a Command (CVE-ID: CVE-2026-44193)

CWE-ID: CWE-88 - Argument Injection or Modification

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a remote user to execute arbitrary code.

The vulnerability exists due to improper neutralization of argument delimiters in a command in the XMLRPC endpoint method opnsense.restore_config_section in src/etc/inc/auth.inc when processing user-supplied XMLRPC configuration data. A remote privileged user can send a specially crafted XMLRPC request to execute arbitrary code.

Exploitation requires access to the XMLRPC endpoint with the XMLRPC Library privilege, and the injected payload is triggered during a synchronization such as reloading all services.

2) Improper Restriction of Excessive Authentication Attempts (CVE-ID: N/A)

CWE-ID: CWE-307 - Improper Restriction of Excessive Authentication Attempts

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green

The vulnerability allows a remote attacker to bypass authentication lockout protections.

The vulnerability exists due to improper restriction of excessive authentication attempts in the lockout_handler when processing authentication syslog events containing attacker-controlled usernames. A remote attacker can submit failed login attempts with a crafted username containing a success keyword to bypass authentication lockout protections.

This impacts both the WebGUI and ssh password login paths.

Remediation

Install update from vendor's website.

References

• https://github.com/opnsense/core/security/advisories/GHSA-xxp9-93cr-x54p
• https://github.com/opnsense/core/security/advisories/GHSA-h3vx-4q27-rc42
• https://github.com/advisories/GHSA-h3vx-4q27-rc42