SkyBridge MB-A100/110: Missing Authentication for Critical Functionality
CVE-2023-23906 is a high-severity missing authentication for critical functionality vulnerability in SkyBridge MB-A100/110 from Seiko Solutions, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected SkyBridge MB-A100/110 versions: firmware Ver. 4.2.0 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.3% chance of exploitation within 30 days, higher than 71% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of SkyBridge MB-A100/110 you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on seiko-sol.co.jp for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Seiko Solutions | SkyBridge MB-A100/110 | firmware Ver. 4.2.0 and earlier | Not stated |
| Seiko-sol | Skybridge Mb-a110 Firmware | 4.2.0 and earlier | Not stated |
| Seiko-sol | Skybridge Mb-a100 Firmware | 4.2.0 and earlier | 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
- NetworkCan be exploited remotely over a network, including the internet.
- 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
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.5 | High | NVD |
| CVSS 3.1 | 7.5 | High | CISA (ADP) |
Official description
Missing authentication for critical function exists in SkyBridge MB-A100/110 firmware Ver. 4.2.0 and earlier, which may allow a remote unauthenticated attacker to execute some critical functions without authentication, e.g., rebooting the product.
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: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Third-party and government advisories
- jvn.jp/en/jp/JVN40604023/Third Party Advisory
Other references
Other vulnerabilities in SkyBridge MB-A100/110
- 7.5 High severity
Recent Missing Authentication for Critical Functionality vulnerabilities
- 8.6 High severity
- 9.8 Critical severity
- 9.1 Critical severity
- 9.8 Critical severity
- 7.5 High severity
- 9.8 Critical severity
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