Serv-U: Incorrect Type Conversion or Cast
CVE-2025-40539 is a high-severity incorrect type conversion or cast vulnerability in Serv-U from SolarWinds, with a CVSS 3.1 base score of 7.2 out of 10. It can be exploited remotely over the network by an attacker with administrator privileges, without any action from a user. Affected Serv-U versions: SolarWinds Serv-U 15.5.3 and prior versions. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.56% 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 Serv-U you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on documentation.solarwinds.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| SolarWinds | Serv-U | SolarWinds Serv-U 15.5.3 and prior 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
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- HighAdministrator-level access is required first.
- 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:H/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 9.1 | Critical | CNA (solarwinds.com) |
| CVSS 3.1 | 7.2 | High | NVD |
Official description
A type confusion vulnerability exists in Serv-U which when exploited, gives a malicious actor the ability to execute arbitrary native code as privileged account. This issue requires administrative privileges to abuse. On Windows deployments, the risk is scored as a medium because services frequently run under less-privileged service accounts by default.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Incorrect Type Conversion or Cast
The product does not correctly convert an object, resource, or structure from one type to a different type.
More Incorrect Type Conversion or Cast vulnerabilities (CWE-704)
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
Advisories
Other vulnerabilities in Serv-U
- 9.1 Critical severity
- 9.1 Critical severity
- 9.1 Critical severity
- 9.1 Critical severity
- 9.1 Critical severity
- 9.1 Critical severity
Recent Incorrect Type Conversion or Cast vulnerabilities
- 7.2 High severity
- 7.1 High severity
- 8.8 High severity
- 8.8 High severity
- 7.8 High severity
- 9.8 Critical severity
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