Frontier X Android application: Missing Authentication for Critical Functionality
CVE-2026-5768 is a high-severity missing authentication for critical functionality vulnerability in Frontier X Android application from Fourth Frontier, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. The record lists version 15.0.0 as the first without the flaw, so updating Frontier X Android application to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.28% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Frontier X Android application to 15.0.0 or a later version.
- Update Frontier X IOS application to 25.0.0 or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Fourth Frontier | Frontier X Android application | before 15.0.0 | 15.0.0 |
| Fourth Frontier | Frontier X IOS application | before 25.0.0 | 25.0.0 |
| Fourth Frontier | Frontier X2 | All versions | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- AdjacentThe attacker must be on the same local network segment.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (hq.dhs.gov).
Official description
The Frontier X2 device allows unauthenticated BLE read/write access to critical GATT characteristics without enforcing pairing authentication or authorization. This allows attackers within BLE range to perform unauthorized control of device functions, including starting/stopping activities, triggering vibrations, causing denial-of-service conditions, and fuzzing characteristic values to induce unexpected behavior. Additionally, the Frontier X mobile application lacks proper BLE device authentication, allowing attackers to impersonate a legitimate Frontier X2 device and connect to the application. By cloning BLE advertisements and exposing expected GATT characteristics, attackers can manipulate activity states and inject fabricated health telemetry such as breathing rate, heart rate, strain, and other health-related data into the mobile application.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Missing Authentication for Critical Functionality
The product does not perform any authentication for functionality that requires a provable user identity or consumes a significant amount of resources.
How developers prevent this class of flaw
- 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 entirely. Then, these modified values would be submitted to the server.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using libraries with authentication capabilities such as OpenSSL or the ESAPI Authenticator.
- When storing data in the cloud (e.g., S3 buckets, Azure blobs, Google Cloud Storage, etc.), use the provider's controls to require strong authentication for users who should be allowed to access the data.
More Missing Authentication for Critical Functionality vulnerabilities (CWE-306)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
Recent Missing Authentication for Critical Functionality vulnerabilities
- 9.1 Critical severity
- 8.8 High severity
- 9.8 Critical severity
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
Spotted an error? Tell us.