VaelsysV4: Incorrect Privilege Assignment
CVE-2025-8261 is a critical-severity incorrect privilege assignment vulnerability in VaelsysV4 from Vaelsys, 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 VaelsysV4 versions: 4.1.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.74% chance of exploitation within 30 days, higher than 55% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of VaelsysV4 you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on vaelsys.github.io 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
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 NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 5.5 | Medium | CNA (vuldb.com) |
| CVSS 3.1 | 7.3 | High | CNA (vuldb.com) |
| CVSS 3.1 | 9.8 | Critical | NVD |
| CVSS 2.0 | 7.5 | High | CNA (vuldb.com) |
Official description
A weakness has been identified in Vaelsys VaelsysV4 4.1.0. This vulnerability affects unknown code of the file /grid/vgrid_server.php of the component User Creation Handler. Executing a manipulation can lead to improper authorization. The attack may be performed from remote. The exploit has been made available to the public and could be used for attacks. The real existence of this vulnerability is still doubted at the moment. The vendor explains: "Based on Vaelsys' analysis, the reported behavior does not allow actions beyond those already permitted to authenticated administrative users, and no change in system configuration or operational practices is necessary."
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Incorrect Privilege Assignment
A product incorrectly assigns a privilege to a particular actor, creating an unintended sphere of control for that actor.
How developers prevent this class of flaw
- Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
- Run your code using the lowest privileges that are required to accomplish the necessary tasks. If possible, create isolated accounts with limited privileges that are only used for a single task. That way, a successful attack will not immediately give the attacker access to the rest of the software or its environment. For example, database applications rarely need to run as the database administrator, especially in day-to-day operations.
More Incorrect Privilege Assignment vulnerabilities (CWE-266)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Technical write-ups (may include proof of concept)
- github.com/waiwai24/0101/blob/main/CVEs/Vaelsys/Unauthorized_User_Creation_Vulnerability_Exists_in_Vaelsys_V4…Exploit, Third Party Advisory
Other vulnerabilities in VaelsysV4
- 7.5 High severity
- 9.8 Critical severity
Recent Incorrect Privilege Assignment vulnerabilities
- 7.2 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 7.3 High severity
- 8.8 High severity
- 9.8 Critical severity
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