Print Spooler Vulnerability

Print Spooler Vulnerability – The Quick Explanatory Guide

Print Spooler Vulnerability
Print Spooler Vulnerability

If you want to know more about Print Spooler Vulnerability, then read on our quick guide to get informed. Vulnerability, in simple terms, is defined as the weakness of a computer that cyber criminals exploit for the purpose of gaining unauthorized access to a specific computer system. Once a vulnerability is exploited, the hacker can easily access all the data present in that system and then he/she may blackmail you to pay in order to recover that. There are so many ways of exploiting the vulnerabilities, the best way to avoid them is to use a tool that will not let the user’s data go online as a result of which the chances of explaining become very less.

What is Print Spooler Vulnerability and Why it is Used?

Microsoft released this vulnerability some time back and named it as PrintNightmare. Once an attacker tries to exploit this vulnerability, he/she can access the domain of your computer system or we can say, the entire computer system. The system may have your personal data also which you must save for which you’ll have to contact security professionals. So, in order to avoid any such issue, the best you can do is to ensure that you make proper arrangements before time.

Print Spooler is basically a service offered by Microsoft to manage and monitor files printing. And almost all Microsoft machines have this default. The products as well as their versions that this vulnerability affects include:

  • Windows Server 2012,2016,2019, 2012 R2, 2008, 2008 R2 and 20H2
  • Windows 7, 10, 8.1, 8.1 RT

Once the hacker gets access to a user’s network, he can connect to the print spooler also, either directly or indirectly. Also, since Print Spooler is in contact with kernel directly, the hacker can easily access the operating system, run any code he/she wants as a result of which the attacker will have easy access to Domain Controller also.

It is usually recommended to not use Domain Controllers as Print Servers. The best reason one can think of having a Print Spooler being run on a DC is due to printer pruning. Apart from the various vulnerabilities present in Print Spooler, a printer bug must also be there to not let the attacker do any harm.


For the above mentioned reasons, the National Cyber Security Authority has advised all the users to:

  • Apply all the security updates as soon as possible. Also, apart from updating these applications, in order to keep the system secure, make sure that a few registry settings are zero.
  • Disable the Print Spooler from all the servers over which you were using it. There are certain commands for that purpose also which you can use in order to ensure that you don’t have to face any malware. That’s the only way to get rid of this vulnerability.

Most security professionals recommend to disable print spooler once you’re done with their usage or when you don’t need that. You can disable it on any machine you’re using it by the use of GP references or by the use of Group Policy Setting, with latter being a good option since you can do it without going through the control panel or any such setting which is not the case in the former.

The Breakdown of Print Spooler Vulnerability

The Print Spooler Vulnerability gets the benefit of RpcAddPrinterDriver function in the service and then clients get the liberty of adding dII files for loading them as SYSTEM. The basic purpose of this function is to ask the users to update their printers remotely. Let’s take an example, an IT person can install your new printer remotely. However, any flaw in the working of this system allows the users to let any of their unsigned dII enter the process. There are so many vulnerabilities seen on daily or weekly basis by IT professionals and not letting the attackers exploit those at any cost is a part of their job.


The companies that are more into their businesses already have arrangements to patch their systems up in order to avoid any malicious activity. Amazon is one of the best examples of it. However, many other organizations do not seem to be ready for any such attack and they end up facing the music in the forms of hacking attacks as a result of which they lose access to their important data. There are some organizations that don’t even know what they should do in this regard and fortune is never kind on them just because of their own laziness. It’s up to the organizations to decide whether or not they want to avoid these issues.




Leave a Comment