CVE-2025-10230
📋 TL;DR
This critical vulnerability in Samba allows unauthenticated remote attackers to execute arbitrary commands on affected systems by sending specially crafted WINS registration packets. The flaw occurs when NetBIOS names are passed to a shell without proper validation, enabling remote code execution as the Samba process. All Samba Active Directory Domain Controllers with the WINS hook enabled are affected.
💻 Affected Systems
- Samba
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attacker to execute arbitrary commands with Samba process privileges, potentially leading to domain takeover, data exfiltration, or ransomware deployment.
Likely Case
Remote code execution leading to installation of backdoors, credential theft, lateral movement within the network, and persistence mechanisms.
If Mitigated
Limited impact if proper network segmentation, egress filtering, and least privilege principles are implemented, though initial compromise of the Samba server remains possible.
🎯 Exploit Status
Exploitation requires sending specially crafted WINS registration packets to the vulnerable Samba server. No authentication is required.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Samba 4.20.0 and later
Vendor Advisory: https://www.samba.org/samba/history/security.html
Restart Required: Yes
Instructions:
1. Download Samba 4.20.0 or later from official sources. 2. Stop Samba services. 3. Backup configuration files. 4. Install updated packages. 5. Restart Samba services. 6. Verify the update was successful.
🔧 Temporary Workarounds
Disable WINS hook
linuxDisable the vulnerable WINS hook functionality if not required
Edit smb.conf and set 'wins hook' to empty or comment out the line
Network segmentation
linuxRestrict access to Samba servers to trusted networks only
iptables -A INPUT -p tcp --dport 137:139 -s trusted_network -j ACCEPT
iptables -A INPUT -p udp --dport 137:139 -s trusted_network -j ACCEPT
iptables -A INPUT -p tcp --dport 137:139 -j DROP
iptables -A INPUT -p udp --dport 137:139 -j DROP
🧯 If You Can't Patch
- Implement strict network access controls to limit Samba server exposure
- Deploy intrusion detection/prevention systems to block WINS registration packet exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check if Samba version is below 4.20.0 and if configured as AD DC with WINS hook enabledCheck Version:
smbd --versionVerify Fix Applied:
Verify Samba version is 4.20.0 or higher and test with vulnerability scanning tools📡 Detection & Monitoring
Log Indicators:
- Unusual shell command execution from Samba process
- Suspicious WINS registration attempts
- Failed command execution attempts in system logs
Network Indicators:
- Unusual WINS registration packets to port 137
- Shell command patterns in NetBIOS name fields
- Multiple rapid WINS registration attempts
SIEM Query:
source="samba" AND (event="wins_hook" OR command="*" OR process="sh" OR process="bash")🔗 References
- https://access.redhat.com/security/cve/CVE-2025-10230
- https://bugzilla.redhat.com/show_bug.cgi?id=2394377
- https://www.samba.org/samba/history/security.html
- https://www.vicarius.io/vsociety/posts/cve-2025-10230-detect-samba-vulnerability
- https://www.vicarius.io/vsociety/posts/cve-2025-10230-mitigate-samba-vulnerability
