Quantum Secular Labs / Blog / Advisories

CVE-2025-54309: CrushFTP Unprotected Alternate Channel Vulnerability

CVE-2025-54309 is rated critical with a CVSS v3.1 base score of 9.8 and affects CrushFTP CrushFTP. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available. CISA added it to its Known Exploited Vulnerabilities catalog on 2025-07-22, which means exploitation in the wild has been observed.

Vulnerability description

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.

Severity breakdown

CVSS v3.1 9.8: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

  • Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
  • Attack complexity: Low. No special conditions; the attack can be repeated reliably.
  • Privileges required: None. No account or prior access is needed.
  • User interaction: None. No action from any user is needed.
  • Scope: Unchanged. Impact stays within the vulnerable component.
  • Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
  • Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
  • Availability impact: High. Total loss of availability; the component can be shut down.

Underlying weakness

CWE-420: Unprotected Alternate Channel

The product protects a primary channel, but it does not use the same level of protection for an alternate channel.

Affected products

  • Crushftp: from 10.0.0 before 10.8.5; from 11.0.0 before 11.3.4_23

References