Improper Input ValidationWeakness · CWE-20

CVE-2025-6625

HIGH · 7.5 CVSS v3.1 Published 2025-08-18
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
CWE-20: Improper Input Validation vulnerability exists that could cause a Denial Of Service when specific crafted FTP command is sent to the device.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

Improper input validation (CWE-20) in the FTP service allows remote attackers to send crafted FTP commands that cause a denial of service. The vulnerability stems from insufficient validation of input data in FTP command handling, leading to service disruption.

MitigationApply vendor patches when available. Until then, restrict FTP access through firewall rules or network segmentation to minimize exposure to untrusted networks.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Confirm FTP service is running
    Use system commands to list active network services (e.g., `netstat -tulpn` or `ss -tulpn`) and look for port 21/FTP listeners. On Linux, also check `/etc/services` for FTP port mapping and use `systemctl list-units --type=service` to find FTP daemon services.
    Affected if An FTP service daemon is actively listening on a network port
  2. Identify FTP server software and version
    Connect to the FTP port (21/tcp) using a client or banner grabber (e.g., `nc -v <host> 21` or `telnet <host> 21`) and capture the server banner. If using an FTP client, the greeting message often reveals the software name and version.
    Affected if The FTP server version matches a known affected version or cannot be determined (unknown version)
  3. Check FTP service network exposure
    Review firewall rules (`iptables -L -n` or `firewall-cmd --list-all`) and network ACLs to determine if port 21 is accessible from external/untrusted IP addresses or the public internet.
    Affected if Port 21/FTP is open to untrusted networks or the internet without restrictive ACLs
  4. Verify FTP command handling configuration
    Examine the FTP server configuration file (e.g., `vsftpd.conf`, `proftpd.conf`, `wu-ftpd` settings in `/etc/`) for any non-standard command restrictions or logging configurations that might indicate command validation issues.
    Affected if The configuration allows anonymous or unrestricted FTP access

If an FTP service is running and accessible from untrusted networks, the environment may be affected by this vulnerability and should be monitored or mitigated until a patch is available.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply vendor patches when available. Until then, restrict FTP access through firewall rules or network segmentation to minimize exposure to untrusted networks.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,750
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Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-6625 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
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  • Version or environment caveats, and links to real fixes
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