Microsoft is battling several security flaws in the Windows Print Spooler service that could allow attackers to remotely control affected systems.
Spooling is the method computers use to store information that is waiting to be executed. An iconic example of spooling is printer memory. When a printer receives an order to print a file, it uses spooling to remember the file’s contents while it is in the process of printing the document.
More than a decade after Microsoft’s deployment, Windows Print Spooler remains a popular target for attackers seeking high-privileged access to corporate networks. Windows Print Spooler, when used, can provide attackers with system-level privileges and the ability to remotely install malware, modify data, and execute malicious code.
For security groups, the service used to manage the printing process in Windows environments is still a huge attack surface that is almost constantly in need of patches and fixes. The experts briefly stated how victims can protect systems from print spooler attacks and, according to the report, there is still no patch for this vulnerability.
Microsoft closed a similar security vulnerability (CVE-2021-1675) in the print spooler on Fix Day in June. DoS vulnerability in print spoolers. This vulnerability, which is caused by SHD files in spoolers, has not yet been fixed because it does not meet security standards, although it can lead to a DoS attack.
Spooling Is Used in Many Hardware Types
One of the most important uses is printing, but it is also the most vulnerable side. First of all, this spooler feature can be found mainly on input and output devices such as keyboard, mouse, printer. Buffering allows an application to run at the speed of the processor while the peripherals run at full speed. SPOOL is a kind of buffer mechanism or process in which data is temporarily stored for use and execution by a device, program, or system.
Buffering, the mechanism used by input and output devices to temporarily store data before it becomes current, is a normal function of the operating system. Pooling is a mechanism where buffering refers to putting data from various input and output jobs into a buffer. Buffering basically overlaps jobs with each other, if one task is running, the array will be replaced with another task, while buffering is a technique that keeps the data along with it for a while and then gets run or run.
In this sense, multiple I/O activities can be performed simultaneously in the spool; for example, multiple I/O tasks can even be running simultaneously when the CPU enters a loop. In spooling, there is no interaction between the I/O device and the CPU. The slower device creates a SPOOL to keep data to be processed queued and the CPU processes it.
Spooling Is More Important for Slow Machines
When the slower device is ready to process a new job, it can read another packet of information from the queue buffer. This data is stored in a buffer called SPOOL until a slower device is ready to work with this data. Print documents are stored in a spool called SPOOL and then added to the print queue. When the printer is ready, it retrieves the data from the print spooler and prints it.
The printer spooler is where your reports can be “lined up” and ready to print after the previous print job has completed. The most common type of spooling is a print spooler, where print jobs are sent to a print spooler before being sent to the printer. Although the term “spooling” refers more to print spooling, other types of data are introduced in some applications.
The idea of spooling dates back to the early days of computers, when input was read from punched cards to print immediately (or process it and then print the result immediately). In the early days of personal computers, users had to wait for documents to print before they could do anything else.
Spooling Becomes an Issue in Complex Environments
In complex work environments where different types of computers with different operating systems are networked together, it is often possible to set up a shared print spool on a shared printer. Document spooling for print and batch job requests continued on the mainframe, with many users sharing a resource pool.
For example, when you print a document from an application, the document data is spooled into temporary storage while the printer warms up. In this case, the affected computer will no longer be able to function as a print server, but will still be able to print locally on the attached printer.
Spooling and Common Windows-related Uses
Windows client and server computers that are not domain controllers can also be affected if Point and Print is enabled or if the Authenticated Users group is nested under another group in the mitigation section. As a safeguard in case an attacker enters the network, only a few people should have access to vital data.
Another way to increase security against such attacks is to set group policies that prevent unprivileged users from accessing the Windows print spooler and allow only them to print. As of this writing, early July 6, 2021, there is still no fix for CVE-2021-34527, and both Microsoft and the Cybersecurity and Infrastructure Security Agency (CISA) are urging administrators to disable the print spooler service. systems not used for printing.
The spooler just needs to notify the remote site when the job is done so that the buffer for the next job can be sent to the remote device. When it actually started working, what and where we clicked in its locked state was executed quickly because all the instructions were downloaded to the appropriate device. A buffer buffer is a waiting station where data can sleep until slower devices like printers catch up. When the faster device sends data to the slower device to do something, it uses any additional auxiliary memory as a SPOOL buffer.