Why SMB 1.0 Is a Security Risk and Should be Disabled!

Why SMB 1.0 Is a Security Risk and Should be Disabled!

SMB 1.0 is an old way computers share files on a network.

It was created decades ago and is no longer safe to use.

Why it’s dangerous

• Hackers know how to break into it

• It has been used in major ransomware attacks that shut down businesses

• It does not protect data as it moves between computers

• Microsoft no longer fixes or supports it
  
  

In simple terms:
Leaving SMB 1.0 turned on is like leaving a door unlocked that criminals already know how to open.

What could happen if SMB 1.0 is enabled

• Viruses can spread from one computer to all others

• Files can be stolen or encrypted (ransomware)

• Your business could be forced offline

• Cyber insurance or compliance requirements may be violated

Why it should be turned off

Modern Windows systems:

• Do not need SMB 1.0

• Have newer, safer methods built in

• Work faster and more securely without it

Microsoft recommends turning it off, and newer versions of Windows already do.

Non-compliance with security standards

Systems with SMB 1.0 enabled commonly fail:

• PCI-DSS

• HIPAA Security Rule

• NIST 800-53

• ISO 27001

• Cyber insurance security requirements

This can result in:

• Audit failures

• Fines

• Denied insurance claims after a breach

What about older programs or devices?

Some very old equipment may still ask for SMB 1.0.

If that happens, we recommend:

• Replacing the old device or software

• Or isolating it so it can’t affect the rest of the network

Recommended security posture

✅ Ensure SMB 1.0 is disabled on all systems
✅ Use SMB 2.1 or SMB 3.x only
✅ Replace or isolate legacy devices requiring SMB1
✅ Block TCP port 445 at the perimeter firewall

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How to Disable SMB 1.0 (Windows)

Option 1: Windows Features (easiest)

1. Open Control Panel

2. Go to Programs → Programs and Features

3. Click Turn Windows features on or off

4. Uncheck:

   • SMB 1.0/CIFS File Sharing Support

5. Click OK

6. Restart the computer

What If Devices Stop Working After Disabling SMB 1.0?

This usually means the device is old and insecure. Common examples:

• Old copiers / scanners

• Legacy NAS devices

• Outdated POS or accounting systems

• Embedded Linux appliances

Here’s what to do next ?

Best Options (In Order)

1. Check for firmware or software updates

Many devices support newer SMB but ship with SMB1 enabled.

• Update firmware

• Enable SMB 2.0 or SMB 3.0 in device settings

? This often fixes the issue without replacing hardware.

Use an alternative method (preferred)

Instead of file sharing:

• Scan to email

• Scan to OneDrive / SharePoint

• Scan to FTP / SFTP

• Use vendor cloud services

This removes SMB entirely from the workflow.

Replace the device (recommended long-term)

If the device:

• Is more than ~7–10 years old

• Only supports SMB1

• Cannot be updated

➡️ Replacement is the secure and recommended option.

This avoids future security risks and compliance problems.

What NOT to Do

❌ Don’t re-enable SMB1 on every PC
❌ Don’t leave it enabled “just in case”
❌ Don’t assume antivirus makes it safe

SMB1 is vulnerable even on “trusted” networks.