BL-AC3600: Use of Hard-coded Credentials
CVE-2025-7564 is a high-severity use of hard-coded credentials vulnerability in BL-AC3600 from Lb-link, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. Affected BL-AC3600 versions: 1.0.22. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.27% 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
- Check which version of BL-AC3600 you run against the affected versions below, and install the vendor's latest release.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| LB-LINK | BL-AC3600 | 1.0.22 | Not stated |
| Lb-link | Bl-ac3600 Firmware | 1.0.22 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
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- 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:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (vuldb.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 7.1 | High | CNA (vuldb.com) |
| CVSS 3.1 | 7.8 | High | CNA (vuldb.com) |
| CVSS 2.0 | 6.8 | Medium | CNA (vuldb.com) |
Official description
A vulnerability, which was classified as critical, has been found in LB-LINK BL-AC3600 1.0.22. Affected by this issue is some unknown functionality of the file /etc/shadow. The manipulation with the input root:blinkadmin leads to hard-coded credentials. Local access is required to approach this attack. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use of Hard-coded Credentials
The product contains hard-coded credentials, such as a password or cryptographic key.
How developers prevent this class of flaw
- For outbound authentication: store passwords, keys, and other credentials outside of the code in a strongly-protected, encrypted configuration file or database that is protected from access by all outsiders, including other local users on the same system. Properly protect the key (CWE-320). If you cannot use encryption to protect the file, then make sure that the permissions are as restrictive as possible. In Windows environments, the Encrypted File System (EFS) may provide some protection.
- For inbound authentication: Rather than hard-code a default username and password, key, or other authentication credentials for first time logins, utilize a first login mode that requires the user to enter a unique strong password or key.
- If the product must contain hard-coded credentials or they cannot be removed, perform access control checks and limit which entities can access the feature that requires the hard-coded credentials. For example, a feature might only be enabled through the system console instead of through a network connection.
More Use of Hard-coded Credentials vulnerabilities (CWE-798)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- vuldb.com/?id.316262Third Party Advisory, VDB Entry
- vuldb.com/?submit.605630Third Party Advisory, VDB Entry
Technical write-ups (may include proof of concept)
- github.com/waiwai24/0101/blob/main/CVEs/Blink/Hardcoded_Credentials_in_BL-AC3600_Routers.mdExploit, Third Party Advisory
- github.com/waiwai24/0101/blob/main/CVEs/Blink/Hardcoded_Credentials_in_BL-AC3600_Routers.md#pocExploit, Third Party Advisory
Other references
- vuldb.com/?ctiid.316262Permissions Required, VDB Entry
Other vulnerabilities in BL-AC3600
- 9.8 Critical severity
- 7.5 High severity
Recent Use of Hard-coded Credentials vulnerabilities
- 10.0 Critical severity
- 9.8 Critical severity
- 7.1 High severity
- 8.8 High severity
- 9.8 Critical severity
- 8.1 High severity
Spotted an error? Tell us.