CrushFTP Max Simultaneous Users From IP
The following analytic identifies instances where CrushFTP has blocked access due to exceeding the maximum number of simultaneous connections from a single IP address. This activity may indicate brute force attempts,…
Description
The following analytic identifies instances where CrushFTP has blocked access due to exceeding the maximum number of simultaneous connections from a single IP address. This activity may indicate brute force attempts, credential stuffing, or automated attacks against the CrushFTP server. This detection is particularly relevant following the discovery of CVE-2025-31161, an authentication bypass vulnerability in CrushFTP versions 10.0.0 through 10.8.3 and 11.0.0 through 11.3.0.
Detection logic
Detection requirements
- Platform
- ContainersESXiIaaSIdentity ProviderLinuxmacOSNetwork DevicesOffice SuiteSaaSWindows
The rule states no platform. This is derived from the ATT&CK technique it maps to.
- Log source category
- crushftp
Known benign triggers
- In environments where multiple users legitimately access CrushFTP from behind the same NAT or proxy, this may generate false positives. Tune the threshold based on your organization's usage patterns.
MITRE ATT&CK mappings
0 exclusive techniques.This is coverage no other published rule has; it is not this rule's total technique count.
References
| Reference | Cited by |
|---|---|
| nvd.nist.gov/vuln/detail/CVE-2025-31161 | 3 |
| www.crushftp.com/crush11wiki/Wiki.jsp?page=Update | 3 |
| www.huntress.com/blog/crushftp-cve-2025-31161-auth-bypass-and-post-exploitation | 3 |
From the source
- At source
- Open at source
- Upstream identifier
- 75dfd9f4-ca64-45d0-9422-4bde6d26a59e
- Tagged by the source as
- CrushFTP VulnerabilitiesWeb ServerwebSplunk CloudSplunk EnterpriseSplunk Enterprise Securitynetwork
Licence
- Published under
- Apache License 2.0Read the licence
- Attribution
- Required
- Obtained under
- Apache-2.0Read the origin licence
Authorship
- Written by
- Published
- Sep 22, 2026
- Version
- 2