What’s Vulnerable › Vulnerabilities

CVE-2023-40044: Progress WS_FTP Server Deserialization of Untrusted Data Vulnerability

• Severity: high (CVSS 8.8 v3.1)
• Exploited in the wild: yes — in CISA KEV since 2023-10-05
• EPSS: 90.4% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2023-09-27 · updated 2026-06-17
• Weakness: CWE-502

Description

In WS_FTP Server versions prior to 8.7.4 and 8.8.2, a pre-authenticated attacker could leverage a .NET deserialization vulnerability in the Ad Hoc Transfer module to execute remote commands on the underlying WS_FTP Server operating system.

Affected products

• Progress Software Corporation WS_FTP Server: before 8.7.4; from 8.8 before 8.8.2 — fixed in 8.7.4, 8.8.2

How to fix

Upgrade to a fixed version: Progress Software Corporation WS_FTP Server 8.7.4, 8.8.2. Check the vendor advisory for mitigations.

References

• http://packetstormsecurity.com/files/174917/Progress-Software-WS_FTP-Unauthenticated-Remote-Code-Execution.html
• https://attackerkb.com/topics/bn32f9sNax/cve-2023-40044
• https://censys.com/cve-2023-40044/
• https://community.progress.com/s/article/WS-FTP-Server-Critical-Vulnerability-September-2023
• https://www.assetnote.io/resources/research/rce-in-progress-ws-ftp-ad-hoc-via-iis-http-modules-cve-2023-40044
• https://www.progress.com/ws_ftp
• https://www.rapid7.com/blog/post/2023/09/29/etr-critical-vulnerabilities-in-ws_ftp-server/
• https://www.theregister.com/2023/10/02/ws_ftp_update/
• http://packetstormsecurity.com/files/174917/Progress-Software-WS_FTP-Unauthenticated-Remote-Code-Execution.html
• https://attackerkb.com/topics/bn32f9sNax/cve-2023-40044
• https://censys.com/cve-2023-40044/
• https://community.progress.com/s/article/WS-FTP-Server-Critical-Vulnerability-September-2023

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