WS_FTP Server Ad Hoc Transfer Module .NET Deserialization Vulnerability

cisa required action Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

1. 2023-09-27 First public exploit (Metasploit exploit/windows/http/ws_ftp_rce_cve_2023_40044)
2. 2023-09-27 Published
3. 2023-10-05 Added to CISA KEV
4. 2023-10-26 CISA patch deadline
5. 2025-02-03 CISA SSVC: exploitation active

Added

3 y ago (2023-10-05)

Patch by

2023-10-26 (3 y ago)

Ransomware

Known to be used in ransomware campaigns

Required action

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Vendor, product

Progress, WS_FTP Server

CISA name

Progress WS_FTP Server Deserialization of Untrusted Data Vulnerability

How it is exploited and what it leads to, in MITRE ATT&CK terms.

• T1059 Command and Scripting Interpreter exploitation
• T1071.002 File Transfer Protocols primary impact
• T1202 Indirect Command Execution secondary impact

kev release 2025-07-28, att&ck v16.1. KEV to ATT&CK mappings by the MITRE Center for Threat-Informed Defense (Mappings Explorer, Apache-2.0). © 2026 The MITRE Corporation. This work is reproduced and distributed with the permission of The MITRE Corporation. Terms of use

Exploitation

Active, exploited in the wild

Automatable

yes

Technical impact

total

Assessed

21 mo ago (2025-02-03)

90.35% chance of exploitation in the next 30 days, higher than 99.8% of all scored CVEs (FIRST EPSS, 2026-11-08).

• Metasploit exploit/windows/http/ws_ftp_rce_cve_2023_40044 Progress Software WS_FTP Unauthenticated Remote Code Execution metasploit exploit, excellent rank, 2023-09-27
• Nuclei template WS_FTP Server - Insecure Deserialization nuclei detection template
• assetnote.io https://www.assetnote.io/resources/research/rce-in-progress-ws-ftp-ad-hoc-via-iis-http-modules-cve-2023-40044 referenced PoC, tagged "exploit" by a source, unverified
• packetstormsecurity.com http://packetstormsecurity.com/files/174917/Progress-Software-WS_FTP-Unauthenticated-Remote-Code-Execution.html referenced PoC, tagged "exploit" by a source, unverified

• Progress Software Corporation WS_FTP Server

Weakness

• CWE-502 Deserialization of Untrusted Data

• assetnote.io /resources/research/rce-in-progress-ws-ftp-ad-hoc-via-iis-http-modules-cve-2023-40044

  exploit, third-party-advisory

• packetstormsecurity.com /files/174917/Progress-Software-WS_FTP-Unauthenticated-Remote-Code-Execution.html

  exploit, third-party-advisory, vdb-entry

• community.progress.com /s/article/WS-FTP-Server-Critical-Vulnerability-September-2023

  vendor-advisory

• progress.com /ws_ftp

  product

• theregister.com /2023/10/02/ws_ftp_update/

  press/media-coverage, third-party-advisory

• rapid7.com /blog/post/2023/09/29/etr-critical-vulnerabilities-in-ws_ftp-server/

  broken-link, third-party-advisory

• attackerkb.com /topics/bn32f9sNax/cve-2023-40044

  third-party-advisory

• censys.com /cve-2023-40044/

  third-party-advisory

• cisa.gov /known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-40044

  government-resource, us-government-resource

• CVE List CVE-2023-40044
• NVD CVE-2023-40044

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.