Detect Soliton FileZen OS Command Injection Exploitation (CVE-2026-25108) in Sumo Logic CSE
Detects exploitation of CVE-2026-25108, an OS command injection vulnerability (CWE-78) in Soliton Systems K.K FileZen file-sharing appliance. This vulnerability is listed on CISA's Known Exploited Vulnerabilities catalog and allows unauthenticated or authenticated attackers to inject arbitrary OS commands through vulnerable input fields, potentially leading to full system compromise.
MITRE ATT&CK
Sumo Detection Query
_sourceCategory=*web* OR _sourceCategory=*access* OR _sourceCategory=*proxy*
| parse "* * * [*] \"* * *\" * *" as src_ip, ident, authuser, datetime, method, uri, protocol, status, bytes nodrop
| where uri matches "*/cgi-bin/*" or uri matches "*/admin/*" or uri matches "*/upload*" or uri matches "*/download*" or uri matches "*/login*"
| where (
uri matches "*;*" or uri matches "*|*" or uri matches "*`*"
or uri matches "*$(*)" or uri matches "*%3B*" or uri matches "*%7C*" or uri matches "*%60*"
or uri matches "*wget*" or uri matches "*curl*" or uri matches "*bash*"
or uri matches "*python*" or uri matches "*perl*" or uri matches "*nc *"
or uri matches "*/etc/passwd*" or uri matches "*/bin/sh*" or uri matches "*/bin/bash*"
)
| fields _messagetime, src_ip, method, uri, status, bytes
| eval injection_type = if(uri matches "*wget*|*curl*|*python*|*perl*", "download_or_exec",
if(uri matches "*nc *|*ncat*|*socat*", "reverse_shell",
if(uri matches "*/etc/passwd*|*/etc/shadow*|*whoami*|*id;*", "recon", "generic_injection")))
| eval cve = "CVE-2026-25108"
| eval severity = "critical"
| count by src_ip, injection_type
| sort by _count descSumo Logic query parsing web access logs to identify HTTP requests to FileZen administrative and file-handling paths that contain OS command injection metacharacters or known exploit tool references, with injection type classification for analyst triage.
Data Sources
Required Tables
False Positives & Tuning
- Automated file processing workflows that construct URLs with encoded special characters for legitimate file operations
- Penetration testing engagements that inject payloads into FileZen endpoints as part of authorized scope
- Log parsing errors that misidentify encoded characters in normal file path parameters as injection attempts
- Security product integrations that append metadata to request URLs using characters that match injection signatures
Other platforms for CVE-2026-25108
Testing Methodology
Validate this detection against 4 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.
- Test 1FileZen-style CGI Command Injection via HTTP GET parameter
Expected signal: Web server access log records GET request to /cgi-bin/upload.cgi with semicolon character in query string. Process audit log shows web server process (httpd/nginx) spawning /bin/sh or /bin/bash as child process executing 'id' command.
- Test 2Post-Exploitation Reverse Shell Download via Injected wget
Expected signal: Web server access log shows POST to /admin/config.cgi with pipe and wget in POST body. Network telemetry shows outbound TCP connection from web server host to ATTACKER_HOST:8080. File creation event for /tmp/payload.sh. Process execution of wget and chmod as children of web server process.
- Test 3Credential and Configuration Exfiltration via Piped cat Command
Expected signal: Web server log records GET request to /download endpoint with URL-encoded pipe and cat command sequence. Network telemetry shows outbound POST connection from FileZen host to ATTACKER_HOST:9090. Process audit captures cat /etc/passwd executed as child of web server process, followed by curl data exfiltration subprocess.
- Test 4Webshell Implantation via Command Injection for Persistent Access
Expected signal: Web server access log records POST to CGI endpoint with semicolon and echo command in body. File creation event for /var/www/html/status.php with PHP content. Process tree shows web server spawning sh executing echo redirection. Subsequent access to /var/www/html/status.php with cmd parameter would indicate webshell usage.
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