Deciso OPNsense diag_backup.php filename Directory Traversal Arbitrary File Creation Vulnerability

published 2025-12-23 10 mo ago modified 2026-10-19 20 d ago also EUVD-2025-204967

cvss: 4.5; version 3.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.6%; EPSS 0.6% chance of exploitation in 30 days, percentile 49%
public exploits: 0; none known

Deciso OPNsense diag_backup.php filename Directory Traversal Arbitrary File Creation Vulnerability. This vulnerability allows network-adjacent attackers to create arbitrary files on affected installations of Deciso OPNsense. Authentication is required to exploit this vulnerability.

The specific flaw exists within the handling of backup configuration files. The issue results from the lack of proper validation of a user-supplied path prior to using it in file operations. An attacker can leverage this vulnerability to create files in the context of root. Was ZDI-CAN-28133.

Patch / fix

links 1

github.com/opnsense/core@cb15c93 commit

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 10 mo ago (2025-12-24)

Exploit prediction

0.61% chance of exploitation in the next 30 days, higher than 49% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.0	4.5	CVSS:3.0/AV:A/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N

Affected products

Deciso OPNsense

Classification

Weakness

CWE-22 Improper Limitation of a Pathname to a Restricted Directory

References

Sources

CVE List CVE-2025-13698
NVD CVE-2025-13698

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary