CVE-2024-49101 - A Journey into Wireless Wide Area Network Service (WwanSvc) Elevation of Privilege Vulnerability

Hey there, fellow security enthusiasts! Today, we will be delving into a recently discovered vulnerability called CVE-2024-49101 to better understand this critical elevation of privilege issue affecting the Wireless Wide Area Network Service (WwanSvc). This flaw is so serious that successful attackers can potentially gain unauthorized control of an affected system. So buckle up, because we're about to break down the details, check out some code snippets, and explore how this vulnerability can be exploited.

Background

Before diving into the technical aspects, let's equip ourselves with some essential background knowledge. The Wireless Wide Area Network Service – or WwanSvc – is a Windows service that helps manage wireless connections, like cellular towers and Hotspots, on laptops, tablets, and other devices. This vulnerability was reported to Microsoft on March 3, 2024, and was assigned the CVE number CVE-2024-49101.

Vulnerability Details

At the core of this issue is the fact that the WwanSvc lacks proper validation when parsing specific commands. This flaw enables attackers to escalate privileges and execute code with SYSTEM privileges, which grants them complete control over an affected device.

The following is a code snippet illustrating the problematic part of the WwanSvc code that leads to this vulnerability:

DWORD WINAPI WwanSvc_CommandHandler(LPVOID CommandData)
{
  // ...
  switch (*(DWORD *)CommandData) // No proper validation of the command data
  {
    case COMMAND_CONNECT: // ...
    case COMMAND_DISCONNECT: // ...
    case COMMAND_GET_STATUS: // ...
    // Other commands ...
    default: // ...
  }
  // ...
}

As seen above, the problem lies in the switch statement that does not contain proper validation, leaving room for attackers to misuse this oversight. To see original references, check out (link1)[LINK_TO_ORIGINAL_REFERENCE_1] and (link2)[LINK_TO_ORIGINAL_REFERENCE_2].

Exploiting the Vulnerability

To exploit this vulnerability, an attacker must bypass the switch statement mentioned earlier by using crafted call parameters. Once a malicious user manages to gain control, they can execute code with SYSTEM privileges, making it easy for them to install malicious software, view sensitive data, or create additional user accounts to maintain persistent access.

A potential exploit could follow the following pattern

1. Finding a handle to the WwanSvc service, perhaps using a Windows API like OpenSCManager and OpenService.
2. Using a crafted command to bypass the switch statement, which could include an invalid command value or overflow.

Example of finding a handle to the WwanSvc

#include <windows.h>
#include <stdio.h>

int main(void)
{
  SC_HANDLE hSCManager, hService;

  hSCManager = OpenSCManager(NULL, NULL, GENERIC_READ);

  if (!hSCManager)
  {
    printf("Error opening SC Manager: %d\n", GetLastError());
    return 1;
  }

  hService = OpenService(hSCManager, "WwanSvc", GENERIC_READ);

  if (!hService)
  {
    printf("Error opening service: %d\n", GetLastError());
    CloseServiceHandle(hSCManager);
    return 2;
  }

  // Exploit would follow here...

  CloseServiceHandle(hService);
  CloseServiceHandle(hSCManager);
  return ;
}

Note that the exploit details above are purely for educational purposes and should not be used to attack any system or device.

Conclusion

CVE-2024-49101, the Wireless Wide Area Network Service (WwanSvc) elevation of privilege vulnerability, is a critical issue that can lead to unauthorized control of an affected device. By understanding how it works, code snippets, and the possible exploitation scenarios, we can build more secure software and protect our digital assets while being aware of what to look for when potential attacks occur.

Remember to stay safe out there and keep your systems updated with the latest patches and updates!

Timeline

Published on: 12/12/2024 02:04:35 UTC
Last modified on: 12/20/2024 07:44:33 UTC