---
title: "CVE-2025-54309:  CrushFTP Unprotected Alternate Channel Vulnerability"
url: https://erroneo.us/security/cve/CVE-2025-54309/
description: "CVE-2025-54309 (CrushFTP CrushFTP): Exploited in the wild (CISA KEV). CrushFTP 10 before 10.8.5 and 11 before 11.3.423, when the DMZ proxy feature is not…"
type: vulnerability-record
section: "Security Digest"
date_published: 2025-07-18
date_modified: 2025-10-21
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2025-54309"
kev: true
cvss: 9
epss: 0.93473
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2025-54309:  CrushFTP Unprotected Alternate Channel Vulnerability

**Signal:** Exploited: patch now if you run it. CISA has confirmed exploitation in the wild. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- Yes, if you run CrushFTP CrushFTP. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2025-07-22, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2025-08-12 ; treat that as the outer limit, not the target.
- EPSS 93.5% , percentile 99.8: FIRST’s model estimates a 93.5% chance of exploitation activity in the next 30 days, higher than 99.8% of all scored CVEs (very high). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.

## What it is

CrushFTP 10 before 10.8.5 and 11 before 11.3.423, when the DMZ proxy feature is not used, mishandles AS2 validation and consequently allows remote attackers to obtain admin access via HTTPS, as exploited in the wild in July 2025.

## Affected products (CVE record)

- CrushFTP CrushFTP: 10 < 10.8.5, 11 < 11.3.4_23

## Severity

- mitre CVSS 3.1: 9 `CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H`

## Exploitation

- CISA KEV: added 2025-07-22; federal due date 2025-08-12. Known ransomware use: Unknown.
- CISA required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
- CISA SSVC assessment: exploitation active , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 93.47% probability of exploitation activity in the next 30 days; percentile 99.8.

## Sources

- [Listed in CISA KEV notes (crushftp.com)](https://www.crushftp.com/crush11wiki/Wiki.jsp?page=CompromiseJuly2025)
- [CVE.org record CVE-2025-54309](https://www.cve.org/CVERecord?id=CVE-2025-54309)
- [NVD entry CVE-2025-54309](https://nvd.nist.gov/vuln/detail/CVE-2025-54309)
- [CISA Known Exploited Vulnerabilities catalog entry](https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-54309)
- [rapid7.com](https://www.rapid7.com/blog/post/crushftp-zero-day-exploited-in-the-wild/)
- [bleepingcomputer.com](https://www.bleepingcomputer.com/news/security/crushftp-zero-day-exploited-in-attacks-to-gain-admin-access-on-servers/)
- [vicarius.io](https://www.vicarius.io/vsociety/posts/cve-2025-54309-detect-crushftp-vulnerability)
- [vicarius.io](https://www.vicarius.io/vsociety/posts/cve-2025-54309-mitigate-crushftp-vulnerability)

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Source page: https://erroneo.us/security/cve/CVE-2025-54309/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt