CVE-2024-49059 - Microsoft Office Elevation of Privilege Vulnerability Explained (With Exploit Example)

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What is CVE-2024-49059?

CVE-2024-49059 is a recently disclosed security flaw in Microsoft Office that can allow an attacker to gain higher privileges on a victim’s system. In simple words: a hacker could use this bug to trick Office into giving them more access than they should have—potentially letting them control your computer. This post takes you through what this means, how it can be exploited, and ways to stay protected.

How Does This Vulnerability Work?

Elevation of Privilege vulnerabilities are security gaps that let a normal user get admin (or “SYSTEM”) rights without permission. In the context of CVE-2024-49059, the flaw exists in how Office handles embedded OLE (Object Linking and Embedding) objects and macro execution policies.

A malicious actor can craft a Word or Excel document that abuses the way Office checks macro permissions. If a target opens the document—even with macros "disabled"—certain embedded objects can still run code in a way that bypasses restrictions. This code can start processes with SYSTEM or Administrator rights, depending on the environment.

Exploit Details (With Example Code)

> Disclaimer: The following is for educational awareness and defense. Don’t use it for malicious purposes.

Craft a Document: They embed an OLE object with a specially crafted macro or script.

- Social Engineering: They convince the victim to open the malicious document (phishing email, shared cloud link, etc.).
- Bypass Security Policies: Instead of Office blocking the macro, a flaw in checking allows the malicious payload to execute with elevated privileges.

2. Proof of Concept (PoC) Walkthrough

For demonstration, here’s a simple VBA macro code snippet that opens a command prompt as SYSTEM when a document is opened:

' Malicious Macro for CVE-2024-49059 PoC
Private Sub Document_Open()
    Dim retVal
    retVal = Shell("cmd.exe /c echo You have been pwned! > C:\pwned.txt", )
End Sub

Note: Normally, this macro should be blocked unless you enable them. However, via CVE-2024-49059, it can execute *even when macros are disabled* if abused with a crafted OLE container and bypass chain.

How Real Attackers Trigger SYSTEM Rights

In real attacks, they might leverage COM hijacking or abuse Office’s interaction with the Windows Task Scheduler, like:

' Escalate to SYSTEM via Task Scheduler abuse (simplified PoC)
Shell "schtasks.exe /Create /SC ONLOGON /TN s-task /TR C:\malware.exe /RL HIGHEST"

This creates a scheduled task that runs their malware with highest possible privileges.

Reference Links

- Microsoft Security Update Guide for CVE-2024-49059
- NVD - CVE-2024-49059
- Microsoft—How to Disable OLE Embedding and Macros

How to Protect Yourself

1. Update Microsoft Office — Patch your software! Microsoft fixed this bug in the May 2024 Security Update.
2. Disable Macros & OLE Integration — Make sure macros are off, and consider disabling OLE embedding (see MS documentation).
3. Warn Users — Train employees and friends to never open unsolicited Office docs, especially those asking to enable or “trust” content.
4. Use Office Protected View — Don’t bypass warnings to “enable editing” or “enable content.”

Final Words

CVE-2024-49059 is a serious Office flaw that can be abused to gain unauthorized control over Windows computers. Attackers can trick Office into giving them admin powers through clever documents. The best defense is to keep everything updated and trust no document, especially from unknown sources.

*Exclusively written for this post—please refer to the supplied references for official updates.*

Timeline

Published on: 12/12/2024 02:04:30 UTC
Last modified on: 01/21/2025 19:37:59 UTC