Threats / CrushFTP / CVE-2024-4040
CVE-2024-4040
· EUVD no mirror located
· GCVE no mirror located
Verified 2026-09-19
CrushFTP vulnerability
CrushFTP contains a sandbox escape vulnerability allowing remote attackers to bypass the virtual file system (VFS) restrictions and access the underlying host system.
Verdict
Today item — known-exploited.
A remote attacker can exploit this unspecified sandbox escape to break out of CrushFTP's VFS isolation, potentially gaining unauthorized access to files and system resources beyond the intended restricted scope.
CISA KEV Yes · 2024-04-245EPSS 0.99539 (verify live)6Exploit Weaponized · public PoC7CVSS 9.83CISA SSVC Exploitation: active · Automatable: yes · Impact: total4
01
Is it exploitable?
— the evidence, ranked above the scoreExploit available
Fully weaponized — public exploit code is cataloged for this vulnerability.We link the existence of the exploit; we do not host or redistribute payloads.
Reported exploitation
211 independent public reports of in-the-wild exploitation are cataloged.Distinct reporting sources (vendor, incident response, government); open them for the underlying claims.
Exploited in the wild
Listed in the CISA Known Exploited Vulnerabilities catalog (added 2024-04-24).
Probability (EPSS)
EPSS 0.99539 — modeled likelihood of exploitation activity.EPSS is a daily-changing model output — open the source for today's value.
Severity / affected
CVSS 9.8 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H) · Affected: CrushFTP, CrushFTP. Confirm exact fixed builds in the vendor advisory.CVSS — CNA-assigned (CVE.org), version 3.1, set at disclosure.
Weakness (CWE)
Mapped to CWE-1336 Template Injection — weakness family: Injection.CWE — CNA-assigned (CVE.org); the weakness class drives how the flaw is exploited.
CISA SSVC (triage disposition)
Exploitation: active · Automatable: yes · Technical Impact: totalCISA's own stakeholder-specific triage inputs, published in the CVE record (CISA Coordinator role). NOTE: this is CISA's three decision points; the final Act/Attend/Track decision also requires a Mission & Well-being input not published here, so no overall decision is asserted.
Currency of the record
CISA added this to its KEV catalog 2 days after the CVE record was published.KEV lag = CISA-KEV dateAdded − CVE.org datePublished; a floor on how long the known-exploited flaw sat in the public record before the federal catalog listed it. Severity/weakness here is CNA- or CISA-assigned (current at disclosure), independent of NVD's analysis backlog.
Public exploit available
Public exploit tooling is catalogued for this CVE (a public proof-of-concept / detection template). Catalog entries: Metasploit module, nuclei template. We link the catalog page(s) only — no payload or code is hosted or restated here.Link, never host — the catalog page is the source; basicsecurity.net does not redistribute payloads.
02
Who’s exploiting it?
— attribution turns risk into urgencyAttribution not established
No confirmed (advisory-backed) threat-actor attribution is established for this record. Absence of a named actor is not absence of compromise — see Coverage & confidence.
03
Why it matters
— the attack path, told twice: adversary, then board1
Front door — unauthenticated access narrative 1
Attacker
I craft a malicious request that exploits the sandbox escape flaw in CrushFTP's VFS boundary enforcement.
Business
The organization's file server is exposed to unauthorized data access and exfiltration beyond configured access controls.
2
Keys to the kingdom — privilege/identity takeover narrative 2
Attacker
I execute commands or access filesystem paths outside the virtual environment that CrushFTP is designed to restrict.
Business
Sensitive files, credentials, and system configuration become accessible to the attacker, compromising confidentiality and integrity.
3
Lateral reach — past segmentation narrative 3
Attacker
I leverage the escaped context to move laterally within the host system or establish persistence.
Business
The breach scope expands beyond the FTP service to the underlying infrastructure, increasing incident response costs and recovery time.
04
What to do
— defensible action- Remediate per the vendor advisory — confirm the fixed build for your version and verify exposure.1
Say it to the boardA vulnerability with this evidence profile is a defensible budget line, not a backlog ticket — fund the change against the proof above.
05
Coverage & confidence
— what we know, and what we don’tEstablished (cited)
Coverage gaps — stated, not hidden
Disclosure & credit2
Catalogued by directcyberCNA
Credited with finding itSimon Garrelou, of Airbus CERTreporter
Found an error? Propose a correction.
A correction is a cited counter-claim — it must cite a source,
gets reviewed by a second human, and is never auto-applied. See the
correction convention and our identity
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