CVE-2025-54309 CrushFTP CrushFTP: software flaw
In plain words: A mistake in the software that attackers have found a way to abuse. Depends on the product — see the description and the vendor advisory.
Confirmed exploited by CISA on · US federal patch deadline Aug 12, 2025
What to do
- Install CrushFTP's security update for CrushFTP. If no update exists, follow the vendor's workaround or stop using the product until one ships.
- Keep a list of every internet-facing server you run so nothing is forgotten.
- Patch anything in this catalog first, ahead of normal patch cycles.
- Put admin and file-transfer apps behind a VPN or single sign-on instead of the open internet.
Who is affected
Work IT. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.
What's at risk: Mass data theft and ransomware: a single flaw in a file-transfer or email server has exposed thousands of organisations at once.
The details
- Official name
- CrushFTP Unprotected Alternate Channel Vulnerability
- Product
- CrushFTP CrushFTP
- CISA description
- CrushFTP contains an unprotected alternate channel vulnerability. When the DMZ proxy feature is not used, mishandles AS2 validation and consequently allows remote attackers to obtain admin access via HTTPS.
- Type of flaw
- Software flaw (CWE-420)
- Confirmed exploited
- Jul 22, 2025
- US federal patch deadline
- Aug 12, 2025
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Answering about CVE-2025-54309 ·
Questions about CVE-2025-54309
Is CVE-2025-54309 being exploited?
Yes. CISA added CVE-2025-54309 to its Known Exploited Vulnerabilities catalog on Jul 22, 2025, which means there is reliable evidence of real-world attacks.
How do I fix CVE-2025-54309?
Install CrushFTP's security update for CrushFTP. If no update exists, follow the vendor's workaround or stop using the product until one ships. Keep a list of every internet-facing server you run so nothing is forgotten.
Am I affected by CVE-2025-54309?
Only if you use CrushFTP CrushFTP. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.