CVE-2023-40044
KEVRansomware UseProgress WS_FTP Server Deserialization of Untrusted Data Vulnerability
Description
Progress WS_FTP Server contains a deserialization of untrusted data vulnerability in the Ad Hoc Transfer module that allows an authenticated attacker to execute remote commands on the underlying operating system.
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.
CVSS 3.1 vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:HPublishedSep 27, 2023
Last modifiedJun 17, 2026
Added to KEVOct 5, 2023
Remediation dueOct 26, 2023
References
- packetstormsecurity.com/files/174917/Progress-Software-WS_FTP-Unauthenticated-Remote-Code-Execution.htmlExploitThird Party Advisory
- attackerkb.com/topics/bn32f9sNax/cve-2023-40044Third Party Advisory
- censys.com/cve-2023-40044/Third Party Advisory
- community.progress.com/s/article/WS-FTP-Server-Critical-Vulnerability-September-2023Vendor Advisory
- assetnote.io/resources/research/rce-in-progress-ws-ftp-ad-hoc-via-iis-http-modules-cve-2023-40044ExploitThird Party Advisory
- progress.com/ws_ftpProduct
- rapid7.com/blog/post/2023/09/29/etr-critical-vulnerabilities-in-ws_ftp-server/Broken LinkThird Party Advisory
- theregister.com/2023/10/02/ws_ftp_update/Press/Media CoverageThird Party Advisory
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-40044US Government Resource
0 recent articles mention this CVE
99
Risk assessment · Critical
Actively exploited and used by ransomware crews. Patch immediately.
- Exploitation
- Confirmed in the wild (CISA KEV)
- Federal remediation deadline
- Overdue by 1097 days
- Ransomware
- Used in known ransomware campaigns
- CVSS
- 10.0 CRITICAL
- EPSS (30-day exploit probability)
- 90.4% · top 1% of all CVEs
- Weakness
- CWE-502
- Attack vector
- Network, remotely reachable
- Preconditions
- No privileges and no user interaction
Recommended actions
- 1.Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
- 2.Treat as emergency change: patch or isolate internet-facing instances first.
- 3.Review exposure: confirm which instances are reachable from the internet and restrict access until patched.
- 4.Hunt for compromise: review logs for the disclosure window, not just from the patch date.
- 5.Verify offline/immutable backups and segment the affected systems. This flaw is used for ransomware initial access.
Assessment is derived automatically from the live signals above; verify against your own asset inventory.