VulnerabilityPublished 9 Mar 2026

CVE-2025-41765: MBS UBR-01 Mk II · Missing Authorization

Affects MBS UBR-01 Mk IISource CVE Database V5

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Not known to be exploited · CVSS 9.1 Critical : upgrade to 6.0.1.0 as a priority.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 3.1 base score

9.1Critical

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

Contested

Critical score, yet low EPSS after six months

EPSS: 0.2% chance of exploitation in 30 days – higher than 19% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 6.0.1.0

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H

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

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

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
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: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 9 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 30 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.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), 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

Upgrade UBR-01 Mk II and UBR-02 and UBR-LON to 6.0.1.0.

Affected software

Product	Affected	Fixed in
MBSUBR-01 Mk II	Affected <6.0.1.0	Fixed in 6.0.1.0
MBSUBR-02	Affected <6.0.1.0	Fixed in 6.0.1.0
MBSUBR-LON	Affected <6.0.1.0	Fixed in 6.0.1.0

AI-suggested

To mitigate CVE-2025-41765, organizations should immediately implement the following specific measures: 1) Restrict network access to the wwwupload.cgi endpoint by applying strict firewall rules or network segmentation to limit exposure only to trusted management networks. 2) Employ intrusion detection/prevention systems (IDS/IPS) to monitor and block unauthorized upload attempts targeting the vulnerable endpoint. 3) If possible, disable or restrict the wwwupload.cgi functionality until a vendor patch is available. 4) Implement strong physical and logical access controls to prevent unauthorized personnel from accessing the device or its management interfaces. 5) Regularly audit device configurations and certificates to detect unauthorized changes or suspicious uploads. 6) Maintain offline, verified backups of device configurations and certificates to enable recovery from compromise. 7) Engage with the vendor (MBS) to obtain timely patches or firmware updates addressing the vulnerability. 8) Consider deploying compensating controls such as application-layer gateways or proxy servers that enforce authentication and authorization on the upload endpoint. 9) Conduct security awareness training for personnel managing these devices to recognize and respond to potential exploitation attempts. These targeted actions go beyond generic advice by focusing on controlling access to the vulnerable interface and monitoring for exploitation attempts in the absence of an immediate patch.

Description

Due to insufficient authorization enforcement, an unauthorized remote attacker can exploit the wwwupload.cgi endpoint to upload and apply arbitrary data. This includes, but is not limited to, contact images, HTTPS certificates, system backups for restoration, server peer configurations, and BACnet/SC server certificates and keys.

Impact

The potential impact of CVE-2025-41765 is severe for organizations worldwide, especially those relying on MBS UBR-01 Mk II devices in industrial, building automation, or critical infrastructure environments. An attacker exploiting this vulnerability can upload malicious or manipulated data to the device, leading to unauthorized configuration changes, replacement of trusted certificates, and restoration of compromised backups. This can result in loss of device integrity, enabling persistent unauthorized control or disruption of services. Availability can also be impacted if the attacker applies corrupted backups or configurations, causing device malfunction or denial of service. The compromise of HTTPS and BACnet/SC certificates can facilitate man-in-the-middle attacks, interception of sensitive communications, or lateral movement within networks. Given the device’s likely deployment in operational technology (OT) environments, exploitation could disrupt critical services such as building management, industrial control systems, or energy distribution. The absence of authentication requirements and user interaction lowers the barrier for attackers, increasing the likelihood of exploitation. The lack of known exploits currently suggests a window of opportunity for defenders to act before widespread attacks occur.

CWE-862Missing Authorization (opens in a new tab)
Class weaknessLikelihood of exploit: HighCWE Top 25 (2025): #4OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product does not perform an authorization check when an actor attempts to access a resource or perform an action.
Architecture and Design
Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) to enforce the roles at the appropriate boundaries.
Architecture and Design
Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
OWASP Cheat Sheets
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.8 (opens in a new tab)
V13.4.2 (opens in a new tab)
V7.2.2 (opens in a new tab)
Attack patterns
Exploitation of Thunderbolt Protection Flaws (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

mbs-solutions.de/mbs-2025-0001 (opens in a new tab)

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 16 Mar 2026, 09:42 UTC

WeaknessesCWE-862

Technical details

References

Community reviews

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