_Discovered in 2024, CVE-2024-43452 is a significant Windows vulnerability involving improper permissions in the Windows Registry. Attackers can use it to gain higher privileges, posing a serious threat to Windows systems worldwide. Here, we’ll explain what this vulnerability is, how it works, show code snippets mimicking the exploit, and share key references for more information._

What is CVE-2024-43452?

CVE-2024-43452 is a newly found _Elevation of Privilege (EoP)_ vulnerability that affects Microsoft Windows operating systems. Essentially, certain registry keys have incorrectly set permissions (Access Control Lists or ACLs), allowing a lower-privileged user to change them, and thus gain admin-level rights. This means any regular user on an affected system can potentially take control, which defeats important security boundaries.

Microsoft’s official advisory is here:
Microsoft Security Advisory for CVE-2024-43452

How Does It Work?

The vulnerability lies in how specific registry keys are protected. Sometimes, these keys are given weaker permissions than intended. An attacker could modify them and, for example, redirect the system to run malicious code with high privileges.

Modify the Key: They change the key’s data to point to their own code or script.

3. Trigger a Privileged Process: When a system process starts up and uses that registry key, it ends up running the attacker’s code as SYSTEM or Administrator.

Example: Simulating the Exploit

Let’s walk through a (redacted and simplified) proof-of-concept you could use in a test environment to better understand the issue.

Important: This example should never be used on production systems. It’s for educational purposes only!

Step 1: List Registry Key Permissions

The main tool to inspect permissions is the built-in icacls command.

C:\> icacls "HKLM\SOFTWARE\VulnerableApp"

You might see something like

Everyone:(OI)(CI)(F)

If Everyone has F (Full control), it is a red flag.

Step 2: Modify the Key as a Regular User

Suppose this key controls what program a privileged service launches. The attacker can set their own value:

Set-ItemProperty -Path "HKLM:\SOFTWARE\VulnerableApp" -Name "Debugger" -Value "C:\Users\Public\malware.exe"

> This replaces a legitimate program with malware—whenever the system launches the service, it will now run the attacker’s code with SYSTEM privileges.

Step 3: Trigger the Exploit

After changing the registry, the attacker waits for the system service to start (or restarts the service), executing their payload.

Patch Your System: Microsoft has released patches. Always update Windows as soon as possible.

- Audit Registry Permissions: Regularly check registry keys (using tools like icacls or Sysinternals AccessChk) to ensure only trusted users and groups have write access.

More Technical References

- Microsoft Security Update Guide - CVE-2024-43452
- Windows Registry Security Best Practices
- Abusing Unsafe Registry Permissions (Blog Post)
- Practical Windows Privilege Escalation (HackTricks)

Final Thoughts

CVE-2024-43452 is a stark reminder that wrong permissions—even in something as tricky as the Windows Registry—can open the door to attackers. With tools and techniques for detecting improper permissions, admins can keep their systems secure, but vigilance and timely patching are key.

Timeline

Published on: 11/12/2024 18:15:22 UTC
Last modified on: 01/01/2025 00:14:27 UTC