{"id":"CVE-2023-40044","published":"2023-09-27T15:18:57Z","modified":"2026-06-17T06:15:55Z","title":"Progress WS_FTP Server Deserialization of Untrusted Data Vulnerability","vendor":"Progress","product":"WS_FTP Server","tier":"core","eol":null,"description":{"text":"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.","provenance":"source","from":"NVD"},"summary":{"text":"The flaw is a .NET deserialization of untrusted data vulnerability in the Ad Hoc Transfer module of Progress WS_FTP Server. It affects WS_FTP Server versions prior to 8.7.4 and 8.8.2. An attacker with network access can exploit it without authenticating to execute remote commands on the underlying operating system of the WS_FTP Server.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-29T07:53:53Z"},"cvss":{"score":8.8,"severity":"HIGH","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","provenance":"source","from":"NVD"},"epss":{"score":0.90355,"percentile":0.99798,"date":"2026-10-29","provenance":"source"},"kev":{"dateAdded":"2023-10-05","dueDate":"2023-10-26","ransomware":true,"requiredAction":"Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.","notes":"https://community.progress.com/s/article/WS-FTP-Server-Critical-Vulnerability-September-2023; https://nvd.nist.gov/vuln/detail/CVE-2023-40044","provenance":"source"},"vulncheckKev":{"dateAdded":"2023-10-01","exploitedFirstSeen":"2023-10-01","ransomware":true,"evidence":[{"url":"https://www.rapid7.com/blog/post/2023/09/29/etr-critical-vulnerabilities-in-ws_ftp-server/","date":"2023-10-01"},{"url":"https://www.huntress.com/blog/critical-vulnerabilities-ws-ftp-exploitation","date":"2023-10-02"},{"url":"https://cyberplace.social/@GossiTheDog/111170422410590021","date":"2023-10-03"},{"url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","date":"2023-10-05"},{"url":"https://www.sentinelone.com/blog/threat-actors-actively-exploiting-progress-ws_ftp-via-multiple-attack-chains/","date":"2023-10-09"},{"url":"https://infosec.exchange/@SophosXOps/111222941977295158","date":"2023-10-12"},{"url":"https://unit42.paloaltonetworks.com/unit42-threat-intelligence-roundup/","date":"2023-12-29"},{"url":"https://www.sentinelone.com/resources/watchtower-end-of-year-report-2023/","date":"2024-01-31"},{"url":"https://go.recordedfuture.com/hubfs/reports/cta-2024-0208.pdf","date":"2024-02-08"},{"url":"https://go.recordedfuture.com/hubfs/reports/ta-2024-0321.pdf","date":"2024-03-21"}],"evidenceTotal":18,"provenance":"source"},"exploited":true,"otx":{"pulseCount":50,"pulses":[{"name":"Actively_Exploited_Kev | Oct 30, 2026","url":"https://otx.alienvault.com/pulse/6ae35d889ea92b4ce19c2680","created":"2026-10-29"},{"name":"Actively_Exploited_Kev | Oct 29, 2026","url":"https://otx.alienvault.com/pulse/6ae20c1db17e7057ae7d9ad1","created":"2026-10-28"},{"name":"Actively_Exploited_Kev | Oct 28, 2026","url":"https://otx.alienvault.com/pulse/6ae0ba7e0e2a97ff7b218819","created":"2026-10-27"},{"name":"Actively_Exploited_Kev | Oct 27, 2026","url":"https://otx.alienvault.com/pulse/6adf68b85c3e852f3c111d18","created":"2026-10-26"},{"name":"Actively_Exploited_Kev | Oct 24, 2026","url":"https://otx.alienvault.com/pulse/6adb740e397c3ad4799aa4cd","created":"2026-10-23"},{"name":"Actively_Exploited_Kev | Oct 23, 2026","url":"https://otx.alienvault.com/pulse/6ada236fcfba2dfa730ea482","created":"2026-10-22"},{"name":"Actively_Exploited_Kev | Oct 22, 2026","url":"https://otx.alienvault.com/pulse/6ad8d33a077cbb5cab524d80","created":"2026-10-21"},{"name":"Actively_Exploited_Kev | Oct 21, 2026","url":"https://otx.alienvault.com/pulse/6ad78130c4d1ac2be83a8b6d","created":"2026-10-20"},{"name":"Actively_Exploited_Kev | Oct 20, 2026","url":"https://otx.alienvault.com/pulse/6ad62f63c24a405a3423cc13","created":"2026-10-19"},{"name":"Actively_Exploited_Kev | Oct 19, 2026","url":"https://otx.alienvault.com/pulse/6ad4dda174e5797d0bd238b7","created":"2026-10-18"}],"provenance":"machine"},"cwes":[{"id":"CWE-502","name":"Deserialization of Untrusted Data"}],"references":[{"url":"http://packetstormsecurity.com/files/174917/Progress-Software-WS_FTP-Unauthenticated-Remote-Code-Execution.html","tags":["Exploit","Third Party Advisory","VDB Entry"]},{"url":"https://attackerkb.com/topics/bn32f9sNax/cve-2023-40044","tags":["Third Party Advisory"]},{"url":"https://censys.com/cve-2023-40044/","tags":["Third Party Advisory"]},{"url":"https://community.progress.com/s/article/WS-FTP-Server-Critical-Vulnerability-September-2023","tags":["Vendor 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Advisory"]},{"url":"https://www.assetnote.io/resources/research/rce-in-progress-ws-ftp-ad-hoc-via-iis-http-modules-cve-2023-40044","tags":["Exploit","Third Party Advisory"]},{"url":"https://www.progress.com/ws_ftp","tags":["Product"]},{"url":"https://www.rapid7.com/blog/post/2023/09/29/etr-critical-vulnerabilities-in-ws_ftp-server/","tags":["Broken Link","Third Party Advisory"]},{"url":"https://www.theregister.com/2023/10/02/ws_ftp_update/","tags":["Press/Media Coverage","Third Party Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-40044","tags":["US Government Resource"]}],"techniques":[{"id":"T1059","name":"Command and Scripting Interpreter","tactics":["execution"],"provenance":"source","basis":"ctid-kev","bases":["ctid-kev"],"basisDetail":"CTID Mappings Explorer KEV 07/28/2025 (ATT&CK 16.1); capability: Deserialization of Untrusted Data","mappingType":"exploitation_technique","evidence":[],"comment":"Zero-day .NET deserialization vulnerability that allows an adversary to make an HTTP POST request to a vulnerable WS_FTP Server and execute commands.","confidence":"high"},{"id":"T1071.002","name":"File Transfer Protocols","tactics":["command-and-control"],"provenance":"source","basis":"ctid-kev","bases":["ctid-kev"],"basisDetail":"CTID Mappings Explorer KEV 07/28/2025 (ATT&CK 16.1); capability: Deserialization of Untrusted Data","mappingType":"primary_impact","evidence":[],"comment":"Zero-day .NET deserialization vulnerability that allows an adversary to make an HTTP POST request to a vulnerable WS_FTP Server and execute commands.","confidence":"high"},{"id":"T1202","name":"Indirect Command Execution","tactics":["stealth"],"provenance":"source","basis":"ctid-kev","bases":["ctid-kev"],"basisDetail":"CTID Mappings Explorer KEV 07/28/2025 (ATT&CK 16.1); capability: Deserialization of Untrusted Data","mappingType":"secondary_impact","evidence":[],"comment":"Zero-day .NET deserialization vulnerability that allows an adversary to make an HTTP POST request to a vulnerable WS_FTP Server and execute commands.","confidence":"high"}],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2023-44651","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2023-44651","exploited":true,"exploitedSince":"2023-10-05","provenance":"source"},"exploits":[],"exploitSources":{"pocGithub":{"count":1,"skipped":0,"earliest":"2023-10-02","earliestUrl":"https://github.com/kenbuckler/WS_FTP-CVE-2023-40044","repos":[{"name":"kenbuckler/WS_FTP-CVE-2023-40044","url":"https://github.com/kenbuckler/WS_FTP-CVE-2023-40044","stars":1,"created":"2023-10-02"}]},"metasploit":[{"name":"Progress Software WS_FTP Unauthenticated Remote Code Execution","module":"exploit/windows/http/ws_ftp_rce_cve_2023_40044","type":"exploit","disclosureDate":"2023-09-27","url":"https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/windows/http/ws_ftp_rce_cve_2023_40044.rb"}],"nuclei":[{"id":"CVE-2023-40044","name":"WS_FTP Server - Insecure Deserialization","severity":"critical","path":"http/cves/2023/CVE-2023-40044.yaml","url":"https://github.com/projectdiscovery/nuclei-templates/blob/main/http/cves/2023/CVE-2023-40044.yaml"}],"first":{"date":"2023-09-27","source":"Metasploit","url":"https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/windows/http/ws_ftp_rce_cve_2023_40044.rb"},"provenance":"source"},"exploitRefs":["http://packetstormsecurity.com/files/174917/Progress-Software-WS_FTP-Unauthenticated-Remote-Code-Execution.html","https://www.assetnote.io/resources/research/rce-in-progress-ws-ftp-ad-hoc-via-iis-http-modules-cve-2023-40044"],"flow":[{"stage":"exploitation","techniques":["T1059"],"provenance":"source"},{"stage":"primary","techniques":["T1071.002"],"provenance":"source"},{"stage":"secondary","techniques":["T1202"],"provenance":"source"}],"timeline":[{"date":"2023-09-27","kind":"published","label":"Published 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