VulnerabilityPublished 23 Dec 2025

CVE-2025-13698: Deciso OPNsense · Path Traversal

Affects Deciso OPNsenseSource CVE Database V5

Not known to be exploited · CVSS 4.5 Medium.

Data as of 26 Oct 2026, 10:12 UTC

CVSS 3.0 base score

4.5Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.6% chance of exploitation in 30 days – higher than 48% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.0/AV:A/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N

Attack Vector: Adjacent
Attack Complexity: Low
Privileges Required: High
User Interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: High
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Adjacent: The vulnerable component is bound to the network stack, but the attack is limited at the protocol level to a logically adjacent topology. This can mean an attack must be launched from the same shared physical (e.g., Bluetooth or IEEE 802.11) or logical (e.g., local IP subnet) network, or from within a secure or otherwise limited administrative domain (e.g., MPLS, secure VPN to an administrative network zone).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: High: The attacker is authorized with (i.e., requires) privileges that provide significant (e.g., administrative) control over the vulnerable component that could affect component-wide settings and files.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: High: There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 23 Dec 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
GitHubopnsense/core`pkg:github/opnsense/core`Other threats	Affected =25.7	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

Immediately verify if your OPNsense deployment is running version 25.7 and assess exposure.
Restrict access to the diag_backup.php interface to trusted administrators only, ideally via VPN or secure management networks.
Implement strict input validation and sanitization on all user-supplied file paths within OPNsense configurations, if customization is possible.
Monitor file system changes on OPNsense devices for unexpected file creations, especially in directories outside the intended backup locations.
Employ file integrity monitoring tools to detect unauthorized modifications or additions.
Limit the privileges of authenticated users to the minimum necessary, reducing the risk of exploitation by compromised accounts.
Regularly audit and rotate administrative credentials to prevent unauthorized access.
Engage with Deciso for official patches or updates addressing this vulnerability and apply them promptly once available.
Consider network segmentation to isolate OPNsense management interfaces from general network traffic.
Document and rehearse incident response plans specific to firewall compromise scenarios.

Description

CVE-2025-13698 is a medium-severity path traversal vulnerability in Deciso OPNsense version 25.7, specifically in the diag_backup.php component. It allows an authenticated network-adjacent attacker to create arbitrary files with root privileges by exploiting improper validation of user-supplied file paths. The vulnerability does not impact confidentiality or availability but can severely affect system integrity. Exploitation requires high privileges (authentication) but no user interaction. There are no known exploits in the wild currently. European organizations using OPNsense 25.7, especially those in critical infrastructure or government sectors, should prioritize patching or mitigating this issue. Mitigations include strict input validation, restricting file write permissions, and monitoring for unusual file creation activities.

Impact

For European organizations, especially those relying on OPNsense 25.7 for firewall and routing functions, this vulnerability poses a risk to system integrity by allowing authenticated attackers to create arbitrary files with root privileges. This could lead to unauthorized code execution, persistent malware implants, or configuration tampering, potentially disrupting network security controls. While confidentiality and availability are not directly impacted, the integrity compromise could facilitate further attacks or lateral movement within networks. Organizations in critical infrastructure, government, finance, and telecommunications sectors are particularly at risk due to the strategic importance of their network security appliances. The requirement for authentication limits the attack surface but does not eliminate risk, especially if credential compromise occurs. The absence of known exploits in the wild provides a window for proactive mitigation. However, failure to address this vulnerability could result in targeted attacks leveraging this flaw to undermine network defenses.

CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') (opens in a new tab)
Base weaknessLikelihood of exploit: HighCWE Top 25 (2025): #6OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
Implementation · Input Validation
Assume all input is malicious. Use an "accept known good" input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
Architecture and Design
For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks…
Implementation · Input Validation
Inputs should be decoded and canonicalized to the application's current internal representation before being validated (CWE-180). Make sure that the application does not decode the same input twice (CWE-174).
OWASP Cheat Sheets
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V12.3.1 (opens in a new tab)
Attack patterns
Path Traversal (opens in a new tab)
Using Slashes and URL Encoding Combined to Bypass Validation Logic (opens in a new tab)
Manipulating Web Input to File System Calls (opens in a new tab)
Using Escaped Slashes in Alternate Encoding (opens in a new tab)
Using Slashes in Alternate Encoding (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 31 Dec 2025, 00:24 UTC

WeaknessesCWE-22

Technical details

References

Community reviews

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