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CVE-2023-40044: Progress WS_FTP Server Deserialization of Untrusted Data Vulnerability

CVSS: 10.0v3.1CriticalKEVRansomwareAnalyzed
Published 27-09-2023Last modified 21-10-2025
Open JSON

Vulnerability summary

CVE-2023-40044 is a critical (CVSS 10.0) Deserialization of Untrusted Data vulnerability in Progress WS_FTP Server. It is known to be exploited: CISA lists it, first on 05-10-2023. It has been used in ransomware campaigns. EPSS estimates a 90.35% chance of exploitation in the next 30 days, higher than 99.8% of scored vulnerabilities. 3 public exploits are recorded.

Overall risk
100/100
0100
Critical · default modelHow is this calculated?
CVSS score
10.0/10
010
Critical · v3.1 (CVE.org)
EPSS score
90.35%
0%100%
Critical · +0.20 pp in 30 days
KEVListedCISA
RansomwareKnown useFlagged by CISA
Public exploits3reference, metasploit

Timeline

  1. 27-09-2023
    PublishedVulnerability first disclosed.
  2. 05-10-2023
    Added to CISA KEVProgress WS_FTP Server Deserialization of Untrusted Data Vulnerability
  3. 26-10-2023
    CISA remediation dueApply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
  4. 21-10-2025
    Last modifiedVulnerability information updated.

Description

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 metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

90.35%

Chance of exploitation in the next 30 days

Percentile

100%

Versus all other CVEs

30-day change

+0.20 pp

From 90.15% on 20-09-2026

20-09-202620-10-2026
EPSS score
90.35%

Known exploited

Compare KEV catalogs
CISA KEVListed
Added
05-10-2023
Federal due date
26-10-2023
Ransomware

CISA required action

Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable. community.progress.com/s/article/WS-FTP-Server-Critical-Vulnerability-September-2023 nvd.nist.gov/vuln/detail/CVE-2023-40044

Public exploits

3 found
  • referenceUnverified

    Exploit Reference (assetnote.io)

    Maturity: unknown

  • referenceUnverified

    Exploit Reference (packetstormsecurity.com)

    Maturity: unknown

  • MetasploitMetasploitremoteVerified

    Progress Software WS_FTP Unauthenticated Remote Code Execution

    exploit/windows/http/ws_ftp_rce_cve_2023_40044

    Maturity: weaponized

Weaknesses

CWE · root cause

Affected systems

Progress1 product
Progress software corporation1 product

2 vendors · 2 products

References

9 links