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  2. Zero-days
  3. CVE-2025-31161
Exploited in the wildUsed by ransomwareServers & business softwareWork IT

CVE-2025-31161 CrushFTP CrushFTP: login or permission bypass

In plain words: A door that should be locked is not: part of the system can be reached without a valid login or permission. The attacker gets in as a user or administrator without knowing a password.

Confirmed exploited by CISA on · US federal patch deadline Apr 28, 2025

What to do

  1. Install CrushFTP's security update for CrushFTP. If no update exists, follow the vendor's workaround or stop using the product until one ships.
  2. Keep a list of every internet-facing server you run so nothing is forgotten.
  3. Patch anything in this catalog first, ahead of normal patch cycles.
  4. Put admin and file-transfer apps behind a VPN or single sign-on instead of the open internet.

Read CrushFTP's advisory ↗

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 Authentication Bypass Vulnerability
Product
CrushFTP CrushFTP
CISA description
CrushFTP contains an authentication bypass vulnerability in the HTTP authorization header that allows a remote unauthenticated attacker to authenticate to any known or guessable user account (e.g., crushadmin), potentially leading to a full compromise.
Type of flaw
Login or permission bypass (CWE-305)
Confirmed exploited
Apr 7, 2025 — known to be used in ransomware attacks
US federal patch deadline
Apr 28, 2025

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Answering about CVE-2025-31161 ·

Questions about CVE-2025-31161

Is CVE-2025-31161 being exploited?

Yes. CISA added CVE-2025-31161 to its Known Exploited Vulnerabilities catalog on Apr 7, 2025, which means there is reliable evidence of real-world attacks, including by ransomware groups.

How do I fix CVE-2025-31161?

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-2025-31161?

Only if you use CrushFTP CrushFTP. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.

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