CVE-2024-4040
CVE-2024-4040 is a security flaw in CrushFTP, software companies use to send and receive files. Attackers can run their own code on CrushFTP 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 24 Apr 2024.[1]
CrushFTP 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 10.7.1 and 11.1.0.
Description
CISA calls it a VFS sandbox escape in CrushFTP CrushFTP. In its words: “CrushFTP contains an unspecified sandbox escape vulnerability that allows a remote attacker to escape the CrushFTP virtual file system (VFS).”[1]
The CVE record adds: “A server side template injection vulnerability in CrushFTP in all versions before 10.7.1 and 11.1.0 on all platforms allows unauthenticated remote attackers to read files from the filesystem outside of the VFS Sandbox, bypass authentication to gain administrative access, and perform remote code execution on the server.”[2]
The underlying weakness is CWE-1336, in MITRE’s list of common software weaknesses.
It scores 10.0 out of 10 on the Common Vulnerability Scoring System, which rates it critical, 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 |
|---|---|
| CrushFTP | 10.7.1 |
| CrushFTP | 11.1.0 |
| crushftp | 10.7.1 |
| crushftp | 11.1.0 |
Most families won’t have CrushFTP; it’s for whoever looks after IT at work.
Exploitation
CISA added it to its catalog of known exploited vulnerabilities on 24 Apr 2024, 2 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 1 May 2024 to fix it.[1]
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 over 99%. 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
CrushFTP 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.CrushFTP 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 10.7.1 and 11.1.0), or not in use. CISA gave US government agencies until 1 May 2024 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 10.0.[2] | |
| CISA adds it to its catalog of flaws known to be used in attacks.[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 over 99%.[4] |
See also
Other CrushFTP flaws
- CVE-2025-54309: unprotected alternate channel ·
- CVE-2025-31161: authentication bypass ·
Similar flaws
- CVE-2026-75650, Adobe Commerce and Magento: improper neutralization of special elements used in a template engine ·
- CVE-2024-23692, Rejetto HTTP File Server: improper neutralization of special elements used in a template engine ·
Added the same day
- CVE-2024-20359, Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD): ASA and FTD privilege escalation ·
- CVE-2024-20353, Cisco Adaptive Security Appliance (ASA) and Firepower Threat Defense (FTD): ASA and FTD denial of service ·
Every CrushFTP flaw on CISA’s list · Everything added in April 2024
References
- ^ Cybersecurity and Infrastructure Security Agency. “CrushFTP VFS Sandbox Escape Vulnerability”. Known Exploited Vulnerabilities Catalog, added 24 Apr 2024.
- ^ National Institute of Standards and Technology. “CVE-2024-4040 Detail”. National Vulnerability Database, published 22 Apr 2024.
- ^ CrushFTP. Advisories and fixes: crushftp.com, crushftp.com, crushftp.com, reddit.com.
- ^ FIRST. “Exploit Prediction Scoring System”. EPSS 0.995, percentile 99.9, 31 Oct 2026.
- CVE Program. “CVE-2024-4040”. 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.