VulnerabilityPublished 9 Mar 2026

CVE-2025-41754: MBS UBR-01 Mk II · Inclusion of Undocumented Features or Chicken Bits

Affects MBS UBR-01 Mk IISource CVE Database V5

Compare

Not known to be exploited · CVSS 6.5 Medium : upgrade to 6.0.1.0 when convenient.

Data as of 29 Oct 2026, 19:04 UTC

CVSS 3.1 base score

6.5Medium

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

EPSS: 0.3% chance of exploitation in 30 days – higher than 29% 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:L/UI:N/S:U/C:H/I:N/A:N

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

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: Low: The attacker is authorized with (i.e., requires) privileges that provide basic user capabilities that could normally affect only settings and files owned by a user. Alternatively, an attacker with Low privileges may have the ability to cause an impact only to non-sensitive resources.
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: High: There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact.
Integrity: None: There is no loss of integrity within 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 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 29 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

Given the absence of official patches, organizations should implement compensating controls to mitigate this vulnerability. First, restrict network access to the MBS UBR-01 Mk II devices by implementing strict firewall rules and network segmentation, limiting access to trusted management networks only. Disable or block access to the wwwubr.cgi interface from untrusted sources. Conduct thorough audits to identify any undocumented or unused API endpoints and disable them if possible. Employ intrusion detection and prevention systems (IDS/IPS) to monitor for suspicious requests targeting the ubr-editfile method or unusual file access patterns. Regularly review device configurations and logs for signs of exploitation attempts. If feasible, engage with the vendor to request a patch or official guidance. Additionally, consider deploying compensating controls such as encrypted storage or access control mechanisms on the device to reduce the impact of unauthorized file reads. Maintain an inventory of affected devices and prioritize remediation efforts based on criticality and exposure. Finally, educate network administrators about the risks of undocumented features and the importance of minimizing attack surfaces in embedded devices.

Description

A low-privileged remote attacker can exploit the ubr-editfile method in wwwubr.cgi, an undocumented and unused API endpoint to read arbitrary files on the system.

Impact

The primary impact of CVE-2025-41754 is the unauthorized disclosure of sensitive information due to arbitrary file read capabilities. This can lead to leakage of configuration files, credentials, or other sensitive data stored on the device, potentially enabling further attacks such as privilege escalation or lateral movement within a network. Although the vulnerability does not allow modification or disruption of services, the confidentiality breach can undermine organizational security postures, especially in environments where the MBS UBR-01 Mk II is used for critical infrastructure or sensitive operations. The ease of remote exploitation without user interaction increases the risk of automated scanning and targeted attacks. Organizations relying on this device may face compliance issues if sensitive data is exposed, and attackers could leverage the information gained to compromise broader network assets. The lack of available patches means the vulnerability may persist for an extended period, increasing exposure. Overall, the impact is significant for confidentiality but limited for integrity and availability.

CWE-1242Inclusion of Undocumented Features or Chicken Bits (opens in a new tab)
Base weakness
The device includes chicken bits or undocumented features that can create entry points for unauthorized actors.
Architecture and Design · Implementation
The implementation of chicken bits in a released product is highly discouraged. If implemented at all, ensure that they are disabled in production devices. All interfaces to a device should be documented.
Attack patterns
Using Unpublished Interfaces or Functionality (opens in a new tab)
Functionality Misuse (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)

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 16 Mar 2026, 09:40 UTC

WeaknessesCWE-1242

Technical details

References

Community reviews

Related threats