In WS_FTP Server version 8.7.0 prior to 8.7.4 and

version 8.8.0 prior to 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.  

References

• https://nvd.nist.gov/vuln/detail/CVE-2023-40044
• https://community.progress.com/s/article/WS-FTP-Server-Critical-Vulnerability-September-2023
• https://www.progress.com/ws_ftp
• https://attackerkb.com/topics/bn32f9sNax/cve-2023-40044
• https://www.assetnote.io/resources/research/rce-in-progress-ws-ftp-ad-hoc-via-iis-http-modules-cve-2023-40044
• http://packetstormsecurity.com/files/174917/Progress-Software-WS_FTP-Unauthenticated-Remote-Code-Execution.html
• https://censys.com/cve-2023-40044
• 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