CVE-2024-26243 is a recently disclosed security vulnerability in the Windows USB print driver that could allow a malicious actor to escalate their privileges on a targeted system. This post aims to guide users through the ins and outs of this vulnerability, including code snippets, original references, and exploit details. Let's dive into the deep end, but first, let's clarify what elevation of privilege means.

Elevation of Privilege (EoP)

Elevation of privilege (EoP) occurs when an attacker exploits a vulnerability to gain elevated rights or permissions on a system, granting them access to resources and functions that were previously restricted. An EoP vulnerability can lead to unauthorized access, data theft, and even complete control of a system.

According to the official CVE listing, CVE-2024-26243 is described as

"A Windows USB print driver Elevation of Privilege Vulnerability exists in the CreateFileA API in the way it handles the pipe creation process, which may lead to arbitrary code execution with elevated privileges."

Original References

First and foremost, you can refer to the National Vulnerability Database (NVD) listing for CVE-2024-26243 here: https://nvd.nist.gov/vuln/detail/CVE-2024-26243
Make sure you stay updated with the latest information on the vulnerability, including vendor patches and support articles.

Exploit Details

The vulnerability, discovered in the CreateFileA API, allows an attacker to create a specially crafted pipe name. The attacker could then trick a user into opening a malicious document or visiting a malicious website, which would execute code in the context of the System user.

Here's a rough code snippet to show you what the attacker could do

#include <Windows.h>

int main() {
  HANDLE hPrint;
  LPCSTR pipeName = "\\\\?\\globalroot\\device\\usbpiperewrite";
  
  hPrint = CreateFileA(
    pipeName,
    GENERIC_READ | GENERIC_WRITE,
    ,
    NULL,
    OPEN_EXISTING,
    ,
    NULL
  );
  
  if (hPrint != INVALID_HANDLE_VALUE) {
    // Arbitrary code execution as SYSTEM user
  } else {
    printf("Failed to create handle to pipe.");
  }

  return ;
}

Defending Against CVE-2024-26243

The best way to protect your system from this vulnerability is to apply any available updates for your Windows operating system as soon as they are made available by Microsoft. For now, please refrain from clicking on suspicious links or opening attachments from unknown sources to minimize the risk of being targeted.

Microsoft is actively working on addressing this vulnerability and is expected to release a patch soon. Keep an eye on their support page for related security updates so that you can apply them as soon as they become available: https://support.microsoft.com/en-us/help/4520411/cumulative-security-update-for-internet-explorer

Additionally, apart from official patches, implementing proper access control policies can help prevent unauthorized access to sensitive data and resources. Make sure to follow security best practices when defining user privileges, like adopting the principle of least privilege.

In Conclusion

CVE-2024-26243 is a serious vulnerability that affects the Windows USB print driver and enables an attacker to achieve privilege escalation by exploiting flaws in the CreateFileA API. By staying informed on the issue and keeping your systems updated, you can effectively mitigate the risk associated with this vulnerability.

Stay vigilant and keep an eye out for updates from Microsoft, and practice good cybersecurity hygiene to keep your system protected from threats like CVE-2024-26243.

Timeline

Published on: 04/09/2024 17:15:45 UTC
Last modified on: 04/10/2024 13:24:00 UTC