- #HP PRINTER UTILITY INSTALL#
- #HP PRINTER UTILITY DRIVERS#
- #HP PRINTER UTILITY DRIVER#
- #HP PRINTER UTILITY PATCH#
- #HP PRINTER UTILITY CODE#
Click the “HP “XXXXX” Basic Drivers” link with “XXXXX” representing your HP printer’s name and then click the “Download” button to start the downloading process.Ĭlick “Save As,” “Save” or similar wording button to save the driver file to your computer when the “Opening XXXXXX” dialog box appears – with “XXXXXX” representing the name of the driver. Click “Next.”Ĭlick the “Driver - Product Installation Software” link. Click the down arrow under “Select your operating system, then click 'Next':” and click on your computer’s operating system. Navigate your computer’s Internet browser to the “HP Customer Care” link and enter your HP printer’s model and number in the box below “Locate your product to get support.” Click the “Next” button.Ĭlick the “Software & Driver Downloads” link. In that buffer, put the address of of system() or exec() or whatever you want to get a shell.Click “Start,” “Shut down” and “Restart” to restart your computer. What's found after the base of the stack? The RIP that's used to return from the NEXT function! So in EBP, write the address of the middle of your buffer. EBP is used as the address of base of the stack after the return. Okay, so either leak the canary and overwrite it with the same value, or - just overwrite EBP.
With modem code, there might be a canary in between EBP and RIP. Let's write the address of system() or exec() in the standard library, shall we? :)
#HP PRINTER UTILITY CODE#
Whatever you write 4-8 bytes past the buffer, that'll be used as the address of the next code to execute. So writing past the end of it means you overwrite EBP and RIP. Where is that buffer? Probably a local variable. You have the local variables, then the saved stack pointer EBP, then RIP - the address of the code to execute on return! But "upside down", with memory addresses going up. Take a look at the standard stack layout. If the extra bytes are *chosen*, it's arbitrary code execution. > but surely if a process suffers a data-error (which, surely is exactly what a buffer-overrun is?), it either stops safely, or signals an error and then stops anyway.Ī buffer overrun is only going to throw an error if it's triggered by a cat walking on the keyboard - of random bytes get written to whatever is after the buffer. "This is not considered best practice since the vulnerable driver can still be used in bring-your-own-vulnerable-driver (BYOVD) attacks." Some Windows machines may already have the vulnerable driver without even running a dedicated installation file, since it comes with Microsoft Windows via Windows Update.
#HP PRINTER UTILITY PATCH#
"While HP is releasing a patch (a fixed driver), it should be noted that the certificate has not yet been revoked at the time of writing," according to SentinelOne. This makes the driver a perfect candidate to target since it will always be loaded on the machine even if there is no printer connected." Affected models and associated patches can be found here and here. In addition, it will be loaded by Windows on every boot. "Whether you are configuring the printer to work wirelessly or via a USB cable, this driver gets loaded. "Thus, in effect, this driver gets installed and loaded without even asking or notifying the user," explained the researchers.
#HP PRINTER UTILITY DRIVERS#
The printer-based attack vector is perfect for cybercriminals, according to SentinelOne, since printer drivers are essentially ubiquitous on Windows machines and are automatically loaded on every startup. "Essentially, this allows attackers to overrun the buffer used by the driver." Thus, unprivileged users can elevate themselves into a SYSTEM account, allowing them to run code in kernel mode, since the vulnerable driver is locally available to anyone, according to the firm. "This function copies a string from the user input using 'strncpy' with a size parameter that is controlled by the user," according to SentinelOne's analysis, released on Tuesday. As the name suggests, IOCTL is a system call for device-specific input/output operations. It carries an 8.8 out of 10 rating on the CVSS scale, making it high-severity.Īccording to researchers, the vulnerability exists in a function inside the driver that accepts data sent from User Mode via Input/Output Control (IOCTL) it does so without validating the size parameter. The bug (CVE-2021-3438) has lurked in systems for 16 years, researchers at SentinelOne said, but was only uncovered this year.
#HP PRINTER UTILITY INSTALL#
If exploited, cyberattackers could bypass security products install programs view, change, encrypt or delete data or create new accounts with more extensive user rights.
An anonymous reader quotes a report from Threatpost: Researchers have released technical details on a high-severity privilege-escalation flaw in HP printer drivers (also used by Samsung and Xerox), which impacts hundreds of millions of Windows machines.