Overview
This blog post will take an in-depth look at the critical vulnerability identified as CVE-2025-7656. This security flaw has significant implications for users of Google Chrome, one of the most widely used internet browsers globally. The vulnerability pertains to an integer overflow in V8, a fundamental part of Google Chrome that executes JavaScript. It allows a remote attacker to potentially exploit heap corruption via a specially crafted HTML page. The severity of this issue is high due to its potential to lead to system compromise or data leakage, highlighting the urgency for users to understand and address it.
Vulnerability Summary
CVE ID: CVE-2025-7656
Severity: High – CVSS Score 8.8
Attack Vector: Network
Privileges Required: None
User Interaction: Required
Impact: System compromise or data leakage upon successful exploit
Affected Products
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Product | Affected Versions
Google Chrome | Prior to 138.0.7204.157
How the Exploit Works
This vulnerability stems from an integer overflow in Google Chrome’s V8 engine. An integer overflow occurs when an arithmetic operation attempts to create a numeric value that is outside of the range that can be represented with a given number of bits. In this case, the overflow results in heap corruption, a type of vulnerability that could allow an attacker to manipulate and control data in the application’s memory.
The threat actor can exploit this vulnerability by creating a malicious HTML page that triggers the integer overflow. When a victim visits this page using a vulnerable version of Google Chrome, the attacker could potentially execute arbitrary code, leading to system compromise or data leakage.
Conceptual Example Code
<!DOCTYPE html>
<html>
<body>
<script type="text/javascript">
// Crafted JavaScript code that triggers integer overflow in V8
var arr = new Array(1);
arr.length = Math.pow(2, 31); // This will cause integer overflow in V8
arr.push('trigger heap corruption'); // Heap corruption due to overflow
</script>
</body>
</html>This conceptual example illustrates a simple JavaScript code that could cause an integer overflow in the V8 engine, leading to heap corruption. Note that actual exploitation would involve more complex manipulations of the memory layout to achieve arbitrary code execution.
Mitigation Guidance
To protect against this vulnerability, users should immediately update their Google Chrome browser to version 138.0.7204.157 or later, which contains a patch for this issue. For those who cannot immediately apply the patch, using a web application firewall (WAF) or intrusion detection system (IDS) can serve as temporary mitigation, as these systems could be configured to detect and block attempts to exploit this vulnerability. Regularly updating and patching software is a critical part of maintaining cybersecurity and preventing potential attacks.