CrushFTP Server Side Template Injection

name: CrushFTP Server Side Template Injection
id: ccf6b7a3-bd39-4bc9-a949-143a8d640dbc
version: 8
creation_date: '2024-06-05'
modification_date: '2026-05-13'
author: Michael Haag, Splunk
status: production
type: TTP
description: This analytic is designed to identify attempts to exploit a server-side template injection vulnerability in CrushFTP, designated as CVE-2024-4040. This severe vulnerability enables unauthenticated remote attackers to access and read files beyond the VFS Sandbox, circumvent authentication protocols, and execute arbitrary commands on the affected server. The issue impacts all versions of CrushFTP up to 10.7.1 and 11.1.0 on all supported platforms. It is highly recommended to apply patches immediately to prevent unauthorized access to the system and avoid potential data compromises. The search specifically looks for patterns in the raw log data that match the exploitation attempts, including READ or WRITE actions, and extracts relevant information such as the protocol, session ID, user, IP address, HTTP method, and the URI queried. It then evaluates these logs to confirm traces of exploitation based on the presence of specific keywords and the originating IP address, counting and sorting these events for further analysis.
data_source:
    - CrushFTP
search: '`crushftp` | rex field=_raw "\[(?<protocol>HTTPS|HTTP):(?<session_id>[^\:]+):(?<user>[^\:]+):(?<src_ip>\d+\.\d+\.\d+\.\d+)\] (?<action>READ|WROTE): \*(?<http_method>[A-Z]+) (?<uri_query>[^\s]+) HTTP/[^\*]+\*" | eval message=if(match(_raw, "INCLUDE") and isnotnull(src_ip), "traces of exploitation by " . src_ip, "false") | search message!=false | rename host as dest | stats count by _time, dest, source, message, src_ip, http_method, uri_query, user, action | sort -_time| `crushftp_server_side_template_injection_filter`'
how_to_implement: CrushFTP Session logs, from Windows or Linux, must be ingested to Splunk. Currently, there is no TA for CrushFTP, so the data must be extracted from the raw logs.
known_false_positives: False positives should be limited, however tune or filter as needed.
references:
    - https://github.com/airbus-cert/CVE-2024-4040
    - https://www.bleepingcomputer.com/news/security/crushftp-warns-users-to-patch-exploited-zero-day-immediately/
finding:
    title: Potential exploitation of CrushFTP Server Side Template Injection Vulnerability on $dest$ by $src_ip$.
    entity:
        field: dest
        type: system
        score: 50
threat_objects:
    - field: src_ip
      type: ip_address
analytic_story:
    - CrushFTP Vulnerabilities
    - Hellcat Ransomware
asset_type: Web Application
cve:
    - CVE-2024-4040
mitre_attack_id:
    - T1190
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: application
security_domain: network