Listen to this Post
The vulnerability, CVE-2025-20229, allows low-privileged attackers to execute arbitrary code by uploading malicious files. Affected versions include:
– Splunk Enterprise before 9.3.3, 9.2.5, and 9.1.8
– Splunk Cloud Platform before 9.3.2408.104, 9.2.2406.108, 9.2.2403.114, and 9.1.2312.208
Vulnerability Details: https://lnkd.in/ghyYthdA
You Should Know:
1. Verify Your Splunk Version
Run this command in Splunk’s CLI to check your version:
splunk version
If your version is vulnerable, immediately update using:
splunk install https://download.splunk.com/products/splunk/releases/[LATEST_VERSION]/linux/splunk-[VERSION]-[BUILD]-Linux-x86_64.tgz
2. Mitigation Steps (If Patching is Delayed)
- Restrict File Uploads: Modify `inputs.conf` to disable unnecessary uploads:
[default] allowUpload = false
- Enforce Least Privilege: Use Splunk’s role-based access control (RBAC):
splunk edit user <username> -role <restricted_role> -auth admin:changeme
3. Detect Exploitation Attempts
Search Splunk logs for suspicious uploads:
index=_internal source=web_service.log "upload" AND "malicious" OR "exec"
4. Linux Workaround (Firewall Rules)
Block unauthorized uploads via `iptables`:
iptables -A INPUT -p tcp --dport 8000 -m string --string "file_upload" --algo bm -j DROP
5. Windows Defender Exclusion (For Splunk Servers)
Prevent false positives during updates:
Add-MpPreference -ExclusionPath "C:\Program Files\Splunk\"
What Undercode Say:
This RCE flaw highlights the risks of insufficient input validation in enterprise logging systems. Always:
– Patch promptly using Splunk’s official channels.
– Monitor file uploads with SIEM rules (e.g., Splunk queries or ELK alerts).
– Harden Splunk deployments by disabling unused services (splunk disable webserver).
For advanced detection, use YARA rules to scan for malicious uploads:
rule splunk_rce_upload {
strings:
$payload = "python -c" nocase
condition:
$payload
}
Expected Output:
Splunk Enterprise 9.3.2 detected. Upgrade to 9.3.3 immediately.
Expected Output:
A detailed mitigation report with patch status, firewall rules, and audit logs.
References:
Reported By: Cybersecurity News – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
