In May 2024, Microsoft disclosed CVE-2024-49033, a critical vulnerability affecting Microsoft Word—a program millions use to open documents every day. Hackers can use this flaw to bypass key security protections in Word, opening the door to targeted attacks. In this post, we’ll walk you through what CVE-2024-49033 is, how attackers exploit it (with code samples), and what you can do to stay safe.

What Is CVE-2024-49033?

CVE-2024-49033 is a security feature bypass vulnerability in Microsoft Word, impacting all supported versions as of spring 2024.

By exploiting this bug, an attacker can craft a malicious document that opens with dangerous content—even if Word’s regular security warnings or protection modes are in place. That means macros, external objects, or other risky code could run unnoticed.

CVSS Score: 7.8 (High)

- Effected Products: Microsoft Word 2013, 2016, Office 2019, Office LTSC, and Office 365 (some unpatched versions)

Attack Vector: Opening a booby-trapped Word file (typically sent in email or downloaded)

> Official Microsoft advisory:
> MSRC - CVE-2024-49033

How Attackers Exploit CVE-2024-49033

This flaw allows attackers to design a document that disables Word’s built-in security prompts—like Protected View or the macro warning banner. Here’s how a basic exploit works:

Attacker builds a malicious Word document.

2. They insert special OLE objects, or tweak internal XML in the file, so Word skips normal protections on open.

Exploit Example: Malicious Macro with Masked Protection

Typical Protected View:
If you download a .docx or .docm file from the internet, Word opens it in "Protected View," where you can’t run macros unless you click "Enable Editing" or "Enable Content."
But with CVE-2024-49033, the attacker can bypass this.

Here’s a simple malicious VBA (Visual Basic for Applications) macro (for testing purposes only)

Sub AutoOpen()
    MsgBox "You have been hacked!"
    ' In real attacks: Download or run malware here
End Sub

Use custom OLE embedding or properties that break Word’s Protected View logic.

- Tools like oletools/olefile or Office Open XML SDK can help manipulate the internal Word structure programmatically.

Pseudocode: Bypassing Security Checks

# Python pseudocode with olefile library
import olefile

doc = olefile.OleFileIO('malicious.docm')
# Modify trusted property or kill Protected View flag
doc.write_stream('WordDocument', b"...modified binary content...")
doc.close()

*Note:* In the wild, attackers use more sophisticated tools to automate these modifications.

In the Wild: Real World Attacks

Threat actors are using spear-phishing emails with “urgent” attachments—like fake invoices or HR forms. If an unpatched user opens the file, malware like Emotet can spread deep inside an organization.

Microsoft reports that Emotet and other malware campaigns have begun exploiting CVE-2024-49033 in June 2024 (Microsoft Threat Intelligence report).

Microsoft has released patches in June 2024 Patch Tuesday.

Check for Updates in your Office client.

Block Macros from the Internet

Use Group Policy to restrict macros from running in files downloaded from email/web:
User Configuration > Administrative Templates > Microsoft Word 2016 > Word Options > Security > Trust Center > Block macros from running in Office files from the Internet

Use Security Tools

Email filtering, Endpoint Detection and Response (EDR), and sandboxing can help catch suspicious files.

More Resources & References

- Microsoft Security Advisory: CVE-2024-49033
- Office Macro Security: Best Practices
- oletools - Analyze OLE and MS Office files
- Safe Documents and Protected View in Word

Conclusion

CVE-2024-49033 shows how clever attackers can sneak past Microsoft Word’s normal defenses with a few technical tricks. Since no warning may appear, even careful users can get infected. Update your software, block macros, and stay alert—because one document is all it takes.

Timeline

Published on: 11/12/2024 18:15:43 UTC
Last modified on: 01/30/2025 00:10:29 UTC