CVE-2025-54309 — CrushFTP Unprotected Alternate Channel Vulnerability
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.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- Confirmed exploitation (CISA KEV)+35
- Public exploit/PoC (github)+6
- EPSS 95.1% (30-day exploitation probability)+15
- Technical severity (critical)+10
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
CISA required action CISA
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
US federal deadline: Aug 12, 2025 — passed 429 day(s) ago
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (CrushFTP CrushFTP).
- Treat as emergency remediation: the CVE is in CISA KEV (confirmed exploitation).
- The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- EPSS ahead of 100% of scored CVEs: prioritize it in the patch queue.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 9.8 | CVSS 3.1 | Critical | 3.9 | 5.9 | nvd@nist.gov via NIST National Vulnerability Database |
| 9.0 | CVSS 3.1 | Critical | 2.2 | 6.0 | cve@mitre.org via NIST National Vulnerability Database |
| 9.0 | CVSS 3.1 | Critical | — | — | GitHub, Inc. via GitHub Security Advisories |
| 9.0 | CVSS 3.1 | Critical | — | — | mitre via CVE Program (cve.org) e CISA ADP |
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
CISA KEV details CISA
CISA lists a CVE once it has evidence of exploitation against real targets.
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 reference date.
Public exploits, PoCs and detection templates
Public code that demonstrates or tests the flaw raises the odds of mass exploitation — and Nuclei templates help find vulnerable assets in your environment.
- watchtowrlabs/watchTowr-vs-CrushFTP-Authentication-Bypass-CVE-2025-54309 ★ 28 Aug 25, 2025
- Exploitation scripts for the CrushFTP CVE-2025-54309: vulnerability ★ 2 Sep 3, 2025
- whisperer1290/CVE-2025-54309__Enhanced_exploit ★ 1 Sep 6, 2025
- 0xLittleSpidy/CVE-2025-54309 ★ 1 Jan 27, 2026
- CrushFTP AS2 Authentication Bypass ★ 0 Aug 29, 2025
- chin-tech/CrushFTP_CVE-2025-54309 ★ 0 Sep 13, 2025
- Findings & july race with 0day in wild ★ 0 Dec 6, 2025
Warning: public PoCs are sometimes disguised malware. Use them only for authorized testing in an isolated environment. This portal does not host exploit code — it only points to the sources.
EPSS over time FIRST
Oct 12, 2026 → Oct 14, 2026 · 3 reading(s) · max 95.11%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Hunt retroactively in logs from before Jul 22, 2025 (KEV listing): exploitation may have started earlier.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · crushftp/crushftp
- CVSS changed · 9.0 → 9.8
- Source status changed · Published → Analyzed
- Record published
- Affected products added · crushftp/crushftp
- CVSS changed · 9.0
- Source status changed · → Published
- SSVC assessment updated
- Added to CISA KEV (detected)
- Record created in this database
- 2025
- Added to CISA KEV catalog
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 3× References added · Oct 13, 2026 – Oct 13, 2026
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
10 on the record
- www.crushftp.com/crush11wiki/Wiki.jsp
- www.cisa.gov/known-exploited-vulnerabilities-catalog
- www.bleepingcomputer.com/news/security/crushftp-zero-day-exploited-in-attacks-to-gain-admin-ac
- www.rapid7.com/blog/post/crushftp-zero-day-exploited-in-the-wild
- www.bleepingcomputer.com/news/security/crushftp-zero-day-exploited-in-attacks-to-gain-admin-ac
- www.vicarius.io/vsociety/posts/cve-2025-54309-detect-crushftp-vulnerability
- github.com/advisories/GHSA-rh5q-v9ww-rqgm
- www.vicarius.io/vsociety/posts/cve-2025-54309-mitigate-crushftp-vulnerability
- www.rapid7.com/blog/post/crushftp-zero-day-exploited-in-the-wild/
- nvd.nist.gov/vuln/detail/CVE-2025-54309
Elsewhere on this site
Related CVEs (same products)
- Medium CVE-2025-63419 Cross-site Scripting (XSS) in CrushFTP Nov 12, 2025
- Medium CVE-2025-63420 Cross-site Scripting (XSS) in CrushFTP Nov 7, 2025
- Critical CVE-2025-31161 CrushFTP Authentication Bypass Vulnerability KEV Apr 3, 2025
- Critical CVE-2024-4040 CrushFTP VFS Sandbox Escape Vulnerability KEV Apr 22, 2024
- Medium CVE-2023-48795 Prefix Truncation Attack against ChaCha20-Poly1305 and Encrypt-then-MAC aka Terrapin Dec 18, 2023
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 fixed version, patch or mitigation documented.
- 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 record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2025-54309 is "CrushFTP Unprotected Alternate Channel Vulnerability", rated Critical. It affects CrushFTP (CrushFTP); versions are in the scope table. It is in CISA KEV: there is evidence of real-world exploitation. CVSS 9.8 describes technical severity. EPSS 95.11% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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