How Can 689 Brother Printer Models Expose Your Network to Devastating Cyberattacks?

Are Brother Printers Dangerously Vulnerable to Hackers?

I need to tell you about something serious that happened with Brother printers. This affects you if you own one of these devices.

Security experts found major problems in Brother printers. These issues are bad enough that hackers can take control of your printer. Let me explain what happened and what you need to do right now.

What Security Experts Found

Rapid7 researchers discovered eight security holes in Brother printers. These problems affect 689 different Brother printer models. But it gets worse - printers from other companies like Fujifilm, Ricoh, Toshiba, and Konica Minolta also have these same issues.

The most dangerous problem is called CVE-2024-51978. This flaw lets hackers figure out your printer's default password just by knowing its serial number. Think about that for a second. Your printer's serial number is often visible or easy to find. Once a hacker has that, they can log into your printer as an admin.

The Critical Password Problem

Here's what makes this so scary. Brother printers create their default passwords using a simple formula based on the serial number. The process works like this:

• Take the first 16 characters of the serial number
• Add some standard data
• Run it through a hash function
• Convert it to a password

This means every Brother printer made before they fixed this problem has a predictable password. Even worse, Brother says they cannot fix this with software updates alone. They had to change how they make printers.

What Hackers Can Do

Once hackers get into your printer, they can:

• Crash your printer repeatedly
• Access files you've scanned
• See your address book
• Get passwords for other network services
• Use your printer to attack other devices on your network
• Run malicious code on your printer

The vulnerabilities range from medium to critical severity, with CVE-2024-51978 receiving the highest 9.8 critical rating.

What You Must Do Right Now

I cannot stress this enough - you need to act immediately if you own a Brother printer. Here's your action plan:

Step 1: Change Your Password

Log into your printer's web interface and change the default admin password right now. This is the most important step.

Step 2: Check If Your Printer Is Affected

Brother created a PDF document that lists all affected models. Find your printer's model number (it's usually on a label on the printer) and check if it's on the list.

Step 3: Update Your Firmware

If Brother has released a firmware update for your model, download and install it immediately. You can find updates on Brother's website or through your printer's admin interface.

Step 4: Apply Workarounds

If no firmware update is available yet, you need to disable certain features:

• Turn off WSD (Web Services for Devices)
• Disable TFTP (Trivial File Transfer Protocol)
• Change all default passwords

The Complete List of Problems

Here are all eight vulnerabilities that researchers found:

• CVE-2017-9765: Stack buffer overflow that can crash your printer
• CVE-2024-2169: Infinite message loop causing denial of service
• CVE-2024-51977: Unauthorized access to sensitive data
• CVE-2024-51978: Password generation flaw (the worst one)
• CVE-2024-51979: Stack overflow leading to code execution
• CVE-2024-51980: Forced TCP connections for remote access
• CVE-2024-51981: Unauthorized HTTP requests to other network devices
• CVE-2024-51983: Device crashes from external input
• CVE-2024-51984: Exposure of stored passwords

Why This Happened

The password generation flaw exists because Brother used a flawed process during manufacturing. They created passwords using serial numbers as the starting point. This seemed like a good idea at the time, but it created a massive security hole.

Security researchers spent over a year working with Brother to fix these problems. The disclosure process started in May 2024, and Brother has been working on solutions since then.

Protecting Your Network

If you cannot update your printer immediately, here's what you should do:

• Keep your printer behind a firewall
• Don't connect it directly to the internet
• Monitor your network for unusual activity
• Consider disconnecting the printer from your network until you can secure it

The Bottom Line

This security flaw affects hundreds of thousands of printers worldwide. The password generation problem cannot be completely fixed with software updates. You must change your default password to stay safe.

Brother has released firmware updates for many affected models, but the core password issue remains for older printers. The company had to change their entire manufacturing process to fix this problem going forward.

Check your printer model against Brother's list. Update your firmware. Change your password. Do this today, not tomorrow. Your network security depends on it.