CVE-2024-4040
About
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.
Rainforest analyst review
CrushFTP contains a server-side template injection flaw in its request handling. An unauthenticated attacker submits input that the server evaluates as a template expression, which breaks out of the VFS sandbox that is supposed to confine users to their own files. From there the attacker reads arbitrary files off the host, bypasses authentication to obtain administrative access, and ultimately executes code on the server — a full pre-auth compromise from a single crafted request.
CrushFTP is a managed file-transfer product, so the data it holds is exactly the sensitive, often-regulated material organizations move between parties, and the same class of target that made other MFT flaws into supply-chain events. Reports of targeted in-the-wild exploitation appeared essentially alongside disclosure, and public proof-of-concept code followed quickly, driving broad opportunistic scanning. Upgrade immediately to 10.7.1 or 11.1.0 or later, and where possible place CrushFTP behind CrushFTP's own DMZ proxy to limit direct exposure. Because the exploitation window opened at disclosure, treat exposed servers as potentially breached: review admin accounts, look for unexpected file reads, and rotate secrets that lived on the host.
References
- https://github.com/airbus-cert/CVE-2024-4040
- https://www.bleepingcomputer.com/news/security/crushftp-warns-users-to-patch-exploited-zero-day-immediately/
- https://www.crushftp.com/crush10wiki/Wiki.jsp?page=Update
- https://www.crushftp.com/crush11wiki/Wiki.jsp?page=Update
- https://www.rapid7.com/blog/post/2024/04/23/etr-unauthenticated-crushftp-zero-day-enables-complete-server-compromise/
- https://www.reddit.com/r/crowdstrike/comments/1c88788/situational_awareness_20240419_crushftp_virtual/
- https://www.reddit.com/r/cybersecurity/comments/1c850i2/all_versions_of_crush_ftp_are_vulnerable/
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2024-4040
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Frequently asked questions
What is CVE-2024-4040?
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.
How severe is CVE-2024-4040?
CVE-2024-4040 carries a CVSS 3.1 base score of 9.8, rated critical. On the Rainforest Risk Index — which weighs the severity alongside how easy the flaw is to reach and how broad its impact is — it scores 99 out of 100, in the critical band.
How is CVE-2024-4040 exploited?
According to the CVSS vector (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H): attack vector Network, attack complexity Low, privileges required None, user interaction None. Impact on confidentiality High, integrity High and availability High.
Which products are affected by CVE-2024-4040?
Public advisories list the following as affected: crushftp. Check the references on this page for the exact versions each vendor confirms.
How do I fix CVE-2024-4040?
Apply the fix the vendor published — the references on this page link to the primary advisories and patches. When patching can't happen right away, reduce the exposure of the affected component and watch it for exploitation attempts. Rainforest customers see this vulnerability correlated to their own assets and prioritized by real exposure, not by score alone.
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