What is CVE-2025-54309?

CVE-2025-54309 is CrushFTP Unprotected Alternate Channel Vulnerability. The supplied enrichment data classifies it as Unclassified mapped to CWE-420 CWE-420.

Which versions are affected?

Affected product and version evidence is listed in the product table above. Current public advisories should be checked for exact version scope before patch targeting is finalized.

Is there active exploitation?

Yes: CISA KEV signal present. If exploitation is not confirmed from current sources, teams should document that status and continue monitoring KEV, vendor, and telemetry updates.

Is there a public exploit?

13 public PoC repositories reported; 3 marked weaponized in current dataset. Public exploit or PoC availability should raise triage priority, especially for exposed or business-critical systems.

How can defenders detect it?

Start with web/proxy/WAF logs, application logs, network IDS/IPS where available. Look for vulnerability-class behavior, product errors, suspicious authentication events, exploit probes, and abnormal process activity based only on evidence that applies to the affected product.

How should teams prioritize it?

Prioritize CVE-2025-54309 using CVSS 9.8, EPSS 95%, KEV status, public PoC status, and asset exposure. Internet-facing, privileged, or business-critical deployments should be handled first.

Are workarounds available?

The supplied mitigation guidance says to apply vendor patches and restrict external exposure until fixed. Fixed-version evidence is listed in the mitigation section above.

Which threat actors are linked publicly?

Publicly linked actor or ransomware signals in the supplied enrichment data: Shadow Network (), The White Company (), Infy (), Hacking Team (). Do not attribute exploitation to a threat actor unless the source evidence explicitly supports that linkage.

What should be done in the next 24 hours?

Identify exposed assets running affected vendor/product/version combinations. Treat as emergency remediation because CISA KEV status is present. Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class. Open remediation tickets with affected assets, owners, evidence status, and detection coverage so decisions are traceable.

CISA KEVcriticalpublic exploit

CVE-2025-54309

CVE-2025-54309 — CrushFTP Unprotected Alternate Channel Vulnerability

Q: Is it in CISA KEV?

Yes. The supplied enrichment data lists CVE-2025-54309 in CISA KEV with required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.. KEV status should be monitored because it can change after initial disclosure or after exploitation becomes publicly confirmed.

CrushFTP 10 before 10.8.5 and 11 before 11.3.4_23, when the DMZ proxy feature is not used, mishandles AS2 validation and consequently allows remote attackers to obtain admin access via HTTPS, as exploited in the wild in July 2025.

Published Jul 18, 2025Updated Jun 17, 2026Sources: NVD, CrushFTP (CNA), CISA, FIRST EPSS, SOCRadar CTI

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.

Exploitation

Confirmed

CISA KEV, listed Jul 22, 2025

EPSS

95%

ahead of 99.9% of scored CVEs

Affects

CrushFTP

2 products listed

CVSS base

9.8

critical · 2 sources

CISA SSVC assessment

Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.

CISA

Exploitation

Active

none · proof-of-concept · active

Automatable

can an attacker script all four kill-chain steps

Technical impact

Total

partial · total control of the vulnerable component

Remediation

The vendor's own words where we have them.

Upgrade CrushFTP to a fixed release. Apply vendor patches per advisory and restrict external exposure of the affected component until patched.

CISA required action

Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Federal deadline Aug 12, 2025 — passed 402 days ago

First 24 hours

Ordered from the record's own fields — exposure first, because you cannot patch what you have not found.

Identify exposed assets running affected vendor/product/version combinations.
Treat as emergency remediation because CISA KEV status is present.
Search available logs for exploit probes, errors, authentication anomalies, or suspicious child processes matching the vulnerability class.

Affected scope

Vendor, product and version as the advisories word them.

Vendor	Product	Versions	Status
CrushFTP	CrushFTP	10 to < 10.8.5	Vulnerable
CrushFTP	CrushFTP	11 to < 11.3.4_23	Vulnerable

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Availability

High

Confidentiality

High

Integrity

High

Scope

Unchanged

Attack Complexity

Low

Attack Vector

Network

Privileges Req

None

User Interaction

None

Every base score collected

Sources score independently and disagree; each row says who scored it and under which version.

Score	Version	Severity	Expl.	Impact	Source
9	CVSS 3.1	critical	2.2	6	MITRE (CNA), CrushFTP (CNA)
9.8	CVSS 3.1	critical	3.9	5.9	NVD

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H

What this weakness leads to

MITRE's own consequences and mitigations for the weakness class — the authority's wording, not guidance derived from the CVSS vector.

MITRE

CWE-420 · Unprotected Alternate Channel

Gain Privileges or Assume Identity
Bypass Protection Mechanism::

Mitigation: Identify all alternate channels and use the same protection mechanisms that are used for the primary channels.::

Weakness & attack patterns

CWE-420

CISA KEV details

CISA lists a CVE here once it has evidence of exploitation against real targets.

CISAThat month →

Listed

Jul 22, 2025

Federal deadline

Aug 12, 2025

passed 402 days ago

Ransomware use

Unknown

CISA records ransomware use only for campaigns it has confirmed, so “Unknown” means unrecorded, not ruled out. The deadline binds US federal agencies; for everyone else it is a date to argue against.

Public exploit

Capability, not use: code existing is a different claim from anyone running it.

Repositories

3 of the 5 sampled are weaponized

Exploit entries

Exploit-DB and CTI exploit indexes

Social mentions

Posts naming this CVE. Attention, not evidence of exploitation — it spikes on disclosure and decays whether or not anything is exploited.

24 more posts on this CVEShowing 5 of 29 · Who is discussing this CVE, and how loudlyUnlock free

Detection

Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.

Prioritize edge telemetry for network-reachable CrushFTP.
Monitor for scanner or exploit-pattern traffic after 13 public PoC repositories were reported.

web/proxy/WAF logsapplication logsnetwork IDS/IPS

Groups associated with this CVE

Groups reported in connection with this vulnerability. A reported association, not a confirmed observation of that group using it — and not scoped to any sector or campaign.

Shadow NetworkThe White CompanyInfyHacking Team

Timeline

What happened to this CVE, newest first — with the readings a source repeats on a schedule counted underneath rather than listed.

2026
Added · CVSS 3.1 9.8 (AV:N)
Jun 17, 2026 · NVD
2025
Added to CISA KEV catalog
Jul 22, 2025 · CISA
Initial · CVE published
Jul 18, 2025 · NVD

Source activity

Readings a source repeats on a schedule, counted rather than listed.

15×SVRS was changedOct 6, 2025 – Jun 11, 2026 · SOCRadar CTI
8×Tweets · 1 time tweeted.Oct 6, 2025 – Aug 25, 2026 · SOCRadar CTI
4×CVE modified by MITRE: CVSS metrics updated.Oct 21, 2025 – Nov 5, 2025 · SOCRadar CTI
2×Github ReposDec 6, 2025 – Jan 27, 2026 · SOCRadar CTI

References

7 on the record

www.bleepingcomputer.com/news/security/crushftp-zero-day-exploited-in-attacks-to-gain-admin-access-on-servers/
Press/Media Coverage, NIST
www.crushftp.com/crush11wiki/Wiki.jsp?page=CompromiseJuly2025
Vendor Advisory, NIST
www.rapid7.com/blog/post/crushftp-zero-day-exploited-in-the-wild/
Press/Media Coverage, NIST
www.vicarius.io/vsociety/posts/cve-2025-54309-detect-crushftp-vulnerability
Third Party Advisory, GITHUB, NIST
www.vicarius.io/vsociety/posts/cve-2025-54309-mitigate-crushftp-vulnerability
Third Party Advisory, GITHUB, NIST
www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-54309
US Government Resource
nvd.nist.gov/vuln/detail/CVE-2025-54309
Vendor Advisory

Coverage

12 stories from the feeds we poll

7 more reports on this CVEShowing 5 of 12 · Vendor research and security press coverageUnlock free

Elsewhere on this site

CrushFTPevery CVE for this vendor
July 2025what else CISA listed
Unclassifiedsame class
CWE-420other pages naming this weakness

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record1

What should defenders know first?

CVE-2025-54309 is CrushFTP Unprotected Alternate Channel Vulnerability, a critical vulnerability affecting CrushFTP from CrushFTP. The current evidence lists it in CISA KEV, and the exploit status is: Yes: CISA KEV signal present. Public exploit evidence is: 13 public PoC repositories reported; 3 marked weaponized in current dataset. The affected-version evidence is listed in the key facts and affected products tables. Defenders should first verify whether exposed or business-critical assets run those versions, then apply vendor patches or mitigations, restrict reachable attack surface, and preserve logs for detection review. CVSS 9.8 describes technical severity, while EPSS 95% helps estimate near-term exploit likelihood; neither replaces asset context. Unknown fields should remain explicit in tickets, and threat actor, IOC, victimology, or payload claims should not be added unless a cited source supports them. Monitor CISA KEV, vendor advisories, NVD changes, public PoC repositories, and internal telemetry for update triggers.