CVE-2023-23601: Critical Cross-Origin Navigation Vulnerability in Firefox, Thunderbird, and Firefox ESR

A newly discovered security vulnerability, CVE-2023-23601, has been identified in Mozilla's popular web browser Firefox, email client Thunderbird, and the extended support release (ESR) version of Firefox. This vulnerability concerns improper handling of cross-origin navigations that could potentially lead to website spoofing attacks. In this detailed post, we will cover the specifics of this vulnerability, the affected versions, and ways to mitigate the risk associated with it.

Vulnerability Details

The core of this vulnerability involves a scenario where URLs can be dragged from a cross-origin iframe into the same tab, allowing unwanted navigation to the dragged URL. This can be exploited by an attacker to perform website spoofing attacks, tricking users into providing sensitive information or performing actions on a malicious website that appears legitimate.

This vulnerability has been assigned the CVE identifier CVE-2023-23601.

To give a clearer picture of the issue, let's look at an example

<!-- Attacker's malicious site -->
<html>
<body>
    <h1>Fake Bank</h1>
    <p>Please visit our sister site:</p>
    <iframe src="https://trustedbank.com/transfers.html"; name="trustedbank" id="trustediframe">
        <!-- Legitimate site rendering within iframe -->
    </iframe>
</body>
<script>
document.getElementById('trustediframe').addEventListener('dragstart', (e) => {
    e.dataTransfer.setData('text/plain', 'https://maliciousbank.com/login.html';);
});
</script>
</html>

In this example, the attacker creates a malicious website with an embedded iframe that displays a legitimate banking website. However, a JavaScript event listener is added to the iframe to trigger a dragstart event. When a user drags the URL from the iframe, they are unknowingly navigating to the attacker's spoofed website.

For more information, please check the following resources

- Official CVE Details: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-23601
- Mozilla Security Advisory: https://www.mozilla.org/en-US/security/advisories/mfsa2023-47/

Exploit Details

To exploit this vulnerability, an attacker would need to create a malicious website containing a cross-origin iframe and craft an event listener to manipulate the dragged URL. Once users visit the malicious website and drag the URL from the iframe, they would be redirected to the attacker-controlled website spoofing a legitimate site.

Firefox ESR: Update to version 102.7 or later.

2. Always verify the website URL before providing any sensitive information or performing any actions. Check for HTTPS and the correct domain name.

3. Use a web browser that offers built-in security features to prevent cross-origin navigations and other security risks.

Conclusion

CVE-2023-23601 is a critical cross-origin navigation vulnerability that affects Firefox, Thunderbird, and Firefox ESR. This vulnerability could allow attackers to perform website spoofing attacks, potentially stealing sensitive information or tricking users into performing unwanted actions. Ensuring that your software is up-to-date, being cautious when interacting with unfamiliar websites, and using security-aware web browsers can help protect you from this vulnerability and similar risks.

Timeline

Published on: 06/02/2023 17:15:00 UTC
Last modified on: 06/08/2023 18:55:00 UTC