New Site Server: Use of Client-Side Authentication
CVE-2025-12868 is a critical-severity use of client-side authentication vulnerability in New Site Server from CyberTutor, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected New Site Server versions: 0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.55% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of New Site Server you run against the affected versions below, and install the vendor's latest release.
- 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 |
|---|---|---|---|
| CyberTutor | New Site Server | 0 | 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
- 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:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (cert.org.tw).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 9.3 | Critical | CNA (cert.org.tw) |
| CVSS 3.1 | 9.8 | Critical | CNA (cert.org.tw) |
Official description
New Site Server developed by CyberTutor has a Use of Client-Side Authentication vulnerability, allowing unauthenticated remote attackers to modify the frontend code to gain administrator privileges on the website.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use of Client-Side Authentication
A client/server product performs authentication within client code but not in server code, allowing server-side authentication to be bypassed via a modified client that omits the authentication check.
How developers prevent this class of flaw
- Do not rely on client side data. Always perform server side authentication.
More Use of Client-Side Authentication vulnerabilities (CWE-603)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
Recent Use of Client-Side Authentication vulnerabilities
- 9.9 Critical severity
- 7.5 High severity
- 7.5 High severity
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