CVE-2023-40044
CVE-2023-40044 is a security flaw in Progress WS_FTP Server. Attackers can run their own code on Progress WS_FTP Server from anywhere, without logging in. The US Cybersecurity and Infrastructure Security Agency (CISA) added it to its catalog of flaws known to be used in attacks on 5 Oct 2023, and says ransomware gangs have used it.[1]
Progress WS_FTP Server is business software or equipment. Most families won’t have it, but attackers break into it to get inside companies, and from there to what those companies hold about their customers, patients and staff. Fixed in version 8.8.2 and 8.7.4 of WS_FTP Server.
Description
CISA calls it a deserialization of untrusted data in Progress WS_FTP Server. In its words: “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.”[1]
The underlying weakness is deserialization of untrusted data (CWE-502), in MITRE’s list of common software weaknesses.[2]
It scores 8.8 out of 10 on the Common Vulnerability Scoring System, which rates it high, scored by NVD using CVSS 3.1.[2]
Affected versions
NVD’s record lists these fixed versions: in each line, everything before the version shown is affected.[2]
| Product | Fixed in |
|---|---|
| WS_FTP Server | 8.8.2 |
| WS_FTP Server | 8.7.4 |
Most families won’t have Progress WS_FTP Server; it’s for whoever looks after IT at work.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 5 Oct 2023, 8 days after it was made public. CISA lists a flaw only when it has reliable evidence of it being exploited, and gave US federal agencies until 26 Oct 2023 to fix it.[1] CISA says ransomware gangs have used it.
FIRST’s Exploit Prediction Scoring System, which estimates how likely a flaw is to be used in attacks in the next 30 days from what it sees across the internet, puts it at 90%. That’s in the top 1% of the flaws it scores.[4]
CISA assesses it as automatable: attackers can run it against many targets at once.
CISA doesn’t say who was attacked, or how.
Fix
Progress has published a fix or advice.[3] CISA’s required action: “Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.”[1]
- Check whether you use it.Progress WS_FTP Server is business software or equipment, so most families won’t have it. If you run a business, or work from home on company equipment, ask whoever looks after your IT.
- Send this page to your IT person.Ask them to confirm it’s fixed (fixed in version 8.8.2 and 8.7.4 of WS_FTP Server), or not in use. CISA gave US government agencies until 26 Oct 2023 to fix it.
- If it can’t be fixed, take it offline.CISA’s advice when there’s no fix is to stop using the product, or take it off the internet, until there is one.
You can’t fix someone else’s server, but you can watch for what follows a break-in like this: a breach notice, a password reset you didn’t ask for, or a scam message that knows things it shouldn’t. HARD watches for those for you and your family.
Timeline
| Date | Event |
|---|---|
| The flaw is made public in the National Vulnerability Database, with a severity score of 8.8.[2] | |
| CISA adds it to its catalog of flaws known to be used in attacks, noting that ransomware gangs have used it.[1] | |
| CISA’s deadline for US government agencies to fix it.[1] | |
| FIRST puts the odds of it being used in attacks in the next 30 days at 90%.[4] |
See also
Other Progress flaws
- CVE-2026-8037, Progress LoadMaster: command injection ·
- CVE-2024-4885, Progress WhatsUp Gold: path traversal ·
- CVE-2024-1212, Progress Kemp LoadMaster: OS command injection ·
- CVE-2024-6670, Progress WhatsUp Gold: SQL injection ·
- CVE-2024-4358, Progress Telerik Report Server: authentication bypass by spoofing ·
Other deserialization of untrusted data flaws
- CVE-2021-23758, Ajax.NET Professional: deserialization of untrusted data ·
- CVE-2026-63077, JetBrains TeamCity: deserialization of untrusted data ·
- CVE-2026-50522, Microsoft SharePoint: deserialization of untrusted data ·
- CVE-2026-58644, Microsoft SharePoint: deserialization of untrusted data ·
- CVE-2026-45659, Microsoft SharePoint Server: deserialization of untrusted data ·
Added the same day
- CVE-2023-42824, Apple iOS and iPadOS: kernel privilege escalation ·
- CVE-2023-22515, Atlassian Confluence Data Center and Server: broken access control ·
Every Progress flaw on CISA’s list · Everything added in October 2023
References
- ^ Cybersecurity and Infrastructure Security Agency. “Progress WS_FTP Server Deserialization of Untrusted Data Vulnerability”. Known Exploited Vulnerabilities Catalog, added 5 Oct 2023.
- ^ National Institute of Standards and Technology. “CVE-2023-40044 Detail”. National Vulnerability Database, published 27 Sep 2023.
- ^ Progress. Advisories and fixes: community.progress.com.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.904, percentile 99.8, 31 Oct 2026.
- CVE Program. “CVE-2023-40044”. The official CVE record.
This article is built from CISA’s catalog (version 2026.10.30), NVD’s record and FIRST’s scores, kept in HARD’s database and checked every morning. The plain English is HARD’s.