CVE-2025-54309: CrushFTP Unprotected Alternate Channel Vulnerability

Patch now

CRITICAL 9.0EXPLOITEDREMOTEUPGRADE

CVE-2025-54309 is a critical-severity flaw (CVSS 9.0) affecting crushftp, reported as exploited in the wild. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

CrushFTP 10 before 10.8.5 and 11 before 11.3.4_23, 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.

Why this priority

Critical severity
EPSS top 1%: very likely to be exploited
Exploited in the wild (CISA KEV)
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.0 (Critical)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	93.5% (top 1%)
CISA exploited list	Yes, fix due 2025-08-12
Weakness	CWE-420
Published	2025-07-18
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: crushftp

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2025-07-18 19:15 UTCPublished CVE record published
2025-07-22Exploited Added to the CISA Known Exploited Vulnerabilities list
2025-08-12Deadline CISA due date for US federal agencies to patch
2026-06-17 09:39 UTCUpdated Record last modified

crushftp crushftp UPGRADE

Affected: >= 10.0.0 and < 10.8.5 · >= 11.0.0 and < 11.3.4_23

Fixed in: 10.8.5, 11.3.4_23

Safe to downgrade to: a release before 10.0.0

1. Check installed version

apt-cache policy crushftp || rpm -q crushftp || crushftp --version

2. UPGRADE to 10.8.5 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade crushftp

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade crushftp

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

3. If no update is available yet, DOWNGRADE to a release before 10.0.0 (Debian / Ubuntu)

apt-cache madison crushftp sudo apt install crushftp=<VERSION_BEFORE_10.0.0> sudo apt-mark hold crushftp

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list crushftp sudo dnf downgrade crushftp-<VERSION_BEFORE_10.0.0> sudo dnf versionlock add crushftp

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

Exact fixes by distribution

Fedora 46 · R · FIXED · 4.6.2-1.fc46 · FEDORA-2026-1dd919a262 · source

sudo dnf upgrade --advisory=FEDORA-2026-1dd919a262

Fedora ELN · perl-Mail-AuthenticationResults · FIXED · 2.20261029-1.eln159 · FEDORA-2026-a2c11d7da6 · source

sudo dnf upgrade --advisory=FEDORA-2026-a2c11d7da6

Public exploits and detection

Public code exists for this CVE. Treat unpatched systems as at risk, and only run PoCs in a lab.

GitHub PoC: watchtowrlabs/watchTowr-vs-CrushFTP-Authentication-Bypass-CVE-2025-54309 (28 stars)
GitHub PoC: foregenix/CVE-2025-54309 (2 stars)
GitHub PoC: whisperer1290/CVE-2025-54309__Enhanced_exploit (1 stars)
Write-up: www.bleepingcomputer.com/news/security/crushftp-zero-day-exploited-in-attacks-to-gain-admi
Write-up: www.vicarius.io/vsociety/posts/cve-2025-54309-detect-crushftp-vulnerability
Write-up: www.vicarius.io/vsociety/posts/cve-2025-54309-mitigate-crushftp-vulnerability
GitHub PoC: blueisbeautiful/CVE-2025-54309
GitHub PoC: brokendreamsclub/CVE-2025-54309

Verify at the official source NVD · CVE Program · CISA KEV catalog · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2025-54309?

crushftp: upgrade to 10.8.5, 11.3.4_23. Exact commands for each OS are on this page.

Is CVE-2025-54309 being exploited?

Yes. CVE-2025-54309 is on the CISA Known Exploited Vulnerabilities list, so treat it as patch-now.

What does CVE-2025-54309 affect?

CVE-2025-54309 affects crushftp. Severity is critical (CVSS 9.0). CrushFTP 10 before 10.8.5 and 11 before 11.3.4_23, 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.

How urgent is CVE-2025-54309?

Priority 91/100. Critical severity; EPSS top 1%: very likely to be exploited; Exploited in the wild (CISA KEV); Public exploit reference; Remotely exploitable, no login, no user action

Related CVEs

CVE-2025-63420 MEDIUM 4.1 UPGRADE CrushFTP11 before 11.3.7_57 is vulnerable to stored HTML injection in the CrushFTP Admin Panel (Reports / "Who
CVE-2025-63419 MEDIUM 6.1 UPGRADE Cross Site Scripting (XSS) vulnerability in CrushFTP 11.3.6_48
CVE-2025-32103 MEDIUM 5.0 UPGRADE CrushFTP 9.x and 10.x through 10.8.4 and 11.x through 11.3.1 allows directory traversal via the /WebInterface/
CVE-2025-32102 MEDIUM 5.0 UPGRADE CrushFTP 9.x and 10.x through 10.8.4 and 11.x through 11.3.1 allows SSRF via the host and port parameters in a
CVE-2025-31161 CRITICAL 9.8 EXPLOITED UPGRADE CrushFTP Authentication Bypass Vulnerability

References

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