Wing FTP Server: External Control of System or Configuration Setting
CVE-2025-27889 is a high-severity external control of system or configuration setting vulnerability in Wing FTP Server from Wftpserver, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, but only if a user takes part, for example by opening a link or file. The record lists version 7.4.4 as the first without the flaw, so updating Wing FTP Server to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.5% 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
- Update Wing FTP Server to 7.4.4 or a later version.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
- Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Wftpserver | Wing FTP Server | before 7.4.4 | 7.4.4 |
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
- RequiredA user must take an action such as opening a file or link.
- 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:R/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 3.4 | Low | CNA (mitre.org) |
| CVSS 3.1 | 8.8 | High | NVD |
Official description
Wing FTP Server before 7.4.4 does not properly validate and sanitize the url parameter of the downloadpass.html endpoint, allowing injection of an arbitrary link. If a user clicks a crafted link, this discloses a cleartext password to the attacker.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: External Control of System or Configuration Setting
One or more system settings or configuration elements can be externally controlled by a user.
How developers prevent this class of flaw
- Compartmentalize the system to have safe areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.
- Because setting manipulation covers a diverse set of functions, any attempt at illustrating it will inevitably be incomplete. Rather than searching for a tight-knit relationship between the functions addressed in the setting manipulation category, take a step back and consider the sorts of system values that an attacker should not be allowed to control.
- In general, do not allow user-provided or otherwise untrusted data to control sensitive values. The leverage that an attacker gains by controlling these values is not always immediately obvious, but do not underestimate the creativity of the attacker.
More External Control of System or Configuration Setting vulnerabilities (CWE-15)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Technical write-ups (may include proof of concept)
- github.com/MrTuxracer/advisories/blob/master/CVEs/CVE-2025-27889.txtExploit, Third Party Advisory
- rcesecurity.com/2025/06/what-the-null-wing-ftp-server-rce-cve-2025-47812/Exploit, Third Party Advisory
Other vulnerabilities in Wing FTP Server
- 4.3 Medium severity
Wing FTP Server Information Disclosure Exploited
- 10.0 Critical severity
Recent External Control of System or Configuration Setting vulnerabilities
- 8.5 High severity
- 7.1 High severity
- 7.2 High severity
- 7.2 High severity
- 7.2 High severity
- 7.2 High severity
Spotted an error? Tell us.