Security Digest · Vulnerability record · Known exploited
CVE-2023-40044: Progress WS_FTP Server Deserialization of Untrusted Data Vulnerability
Exploited in the wild (CISA KEV). In WSFTP 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 WSFTP Server operating system.
CISA KEV · added 2023-10-05 CVSS 10.0 Critical EPSS 90.4% · p99.8
Should you act?
Exploited: patch now if you run it
CISA has confirmed exploitation in the wild. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.
- Yes, if you run Progress WS_FTP Server. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2023-10-05, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2023-10-26; treat that as the outer limit, not the target. CISA also lists it as known to be used in ransomware campaigns.
- EPSS 90.4%, percentile 99.8: FIRST’s model estimates a 90.4% chance of exploitation activity in the next 30 days, higher than 99.8% of all scored CVEs (very high). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
What it is
In WSFTP 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 WSFTP Server operating system.
CISA’s summary
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.
Weakness type: CWE-502.
Product: Progress WS_FTP Server · Assigned by: ProgressSoftware · Published: 2023-09-27
Affected and fixed versions
| Vendor | Product | Affected versions (per CVE record) |
|---|---|---|
| Progress Software Corporation | WS_FTP Server | 8.8.0 < 8.8.2, 8.7.0 < 8.7.4 |
Severity scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| ProgressSoftware | 3.1 | 10 Critical | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |
- Attack vector: network (remotely reachable)
- Attack complexity: low
- Privileges required: none (no login)
- User interaction: none
- Scope: changed (can affect other components)
CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.
Exploitation and urgency
- CISA KEV: added 2023-10-05; federal due date 2023-10-26. Known ransomware use: Known.
- CISA required action: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
- CISA SSVC assessment: exploitation active, automatable yes, technical impact total.
- FIRST EPSS (model of 2026-10-21): 90.35% probability of exploitation activity in the next 30 days; percentile 99.8.
Timeline
- — CVE record published by ProgressSoftware
- — Added to CISA’s Known Exploited Vulnerabilities catalog
- — CISA remediation deadline for US federal agencies
- — CVE record last updated
Sources and references
Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.
Vendor and project advisories, patches
- community.progress.com community.progress.com
Vulnerability records
- CVE.org record CVE-2023-40044 cve.org
- NVD entry CVE-2023-40044 nvd.nist.gov
Government
Other references from the CVE record and advisory
- progress.com progress.com
- theregister.com theregister.com
- rapid7.com rapid7.com
- attackerkb.com attackerkb.com
- censys.com censys.com
- assetnote.io assetnote.io
- packetstormsecurity.com packetstormsecurity.com
All exploited Progress vulnerabilities · Today’s Security Digest