Chrome Vulnerabilities Exploiting Heap Corruption

 Chrome Vulnerabilities Exploiting Heap Corruption 

Introduction

Google Chrome is one of the most widely used web browsers, making it a prime target for security researchers and attackers. Two recently disclosed vulnerabilities—CVE-2025-5419 (Out-of-Bounds Read/Write in V8) and CVE-2025-5068 (Use-After-Free in Blink)—highlight critical memory corruption issues that could allow remote attackers to execute arbitrary code via crafted HTML pages. This article provides an in-depth analysis of these vulnerabilities, including sample attack scenarios and mitigation strategies. 

1. CVE-2025-5419: Out-of-Bounds Read/Write in V8 Engine

Overview

• CVE ID: CVE-2025-5419
• Affected Versions: Google Chrome prior to 137.0.7151.68
• Severity: High (Chromium Security Rating)
• Published Date: June 02, 2025
• Vulnerability Type: Out-of-Bounds (OOB) Read/Write in V8 JavaScript Engine

Technical Analysis

The V8 engine is Chrome’s JavaScript execution component. An out-of-bounds (OOB) read/write vulnerability occurs when a program accesses memory outside the bounds of an allocated buffer. In this case, a maliciously crafted HTML page could trigger improper memory access in V8, leading to heap corruption and potential remote code execution (RCE). 

Root Cause

• Improper bounds checking in array or typed array operations in V8.
• An attacker could manipulate JavaScript objects to read/write beyond intended memory regions.
• Exploitation could lead to arbitrary code execution or browser crashes (DoS).

Sample Exploit Scenario

Consider a malicious website embedding the following JavaScript:

// Triggering OOB access in V8
function triggerOOB() {
    let arr = new Array(10).fill(0x41); // Allocate an array
    let evil = { 
        [Symbol.toPrimitive]() { 
            arr.length = 0; // Force a length change to confuse V8 bounds checking
            return 0xdeadbeef; 
        } 
    };

    // Attempt OOB access
    arr[evil] = 0x42424242; // Corrupts adjacent memory
}

// Load exploit when page opens
window.onload = triggerOOB;

Impact

• An attacker could leak sensitive memory (OOB Read) or overwrite critical pointers (OOB Write).
• Successful exploitation could lead to RCE within Chrome’s sandbox, though escaping the sandbox would require additional exploits.

2. CVE-2025-5068: Use-After-Free in Blink Engine

Overview

• CVE ID: CVE-2025-5068
• Affected Versions: Google Chrome prior to 137.0.7151.68
• Severity: Medium (Chromium Security Rating)
• Published Date: June 02, 2025
• Vulnerability Type: Use-After-Free (UAF) in Blink Rendering Engine

Technical Analysis 

The Blink engine handles DOM rendering in Chrome. A Use-After-Free (UAF) occurs when a program continues to use a pointer after freeing the associated memory. A crafted HTML page could manipulate DOM elements in a way that triggers a UAF, leading to heap corruption.

Root Cause

• Improper cleanup of DOM objects after certain operations (e.g., element removal, event handling).
• An attacker could reallocate freed memory with controlled data, leading to arbitrary code execution.

Sample Exploit Scenario

<!-- Malicious HTML triggering UAF in Blink -->
<script>
function triggerUAF() {
    let element = document.createElement('div');
    document.body.appendChild(element);

    // Register an event handler
    element.addEventListener('click', function() {
        console.log("This memory is freed but still referenced!");
    });

    // Force removal of the element while keeping the event reference
    document.body.removeChild(element);

    // Trigger the event (UAF)
    setTimeout(() => {
        element.dispatchEvent(new Event('click')); // Use-after-free occurs here
    }, 1000);
}

// Execute on page load
window.onload = triggerUAF;
</script>

Impact

• A remote attacker could crash the browser (DoS) or execute arbitrary code.
• Combined with other exploits, this could lead to full browser compromise.

Mitigation & Patch Status

Both vulnerabilities were patched in Chrome 137.0.7151.68. Users should:

1. Update Chrome immediately (Check chrome://settings/help).
2. Enable Site Isolation (chrome://flags/#enable-site-per-process) to mitigate some exploitation attempts.
3. Disable JavaScript for untrusted sites (if feasible).

Conclusion 

• CVE-2025-5419 (OOB in V8) and CVE-2025-5068 (UAF in Blink) are serious memory corruption flaws.
• Attackers could exploit them via crafted HTML/JS, leading to RCE or browser crashes.
• Users must update Chrome to the latest version to stay protected.

These vulnerabilities highlight the importance of memory safety in browsers and the need for continuous security hardening in Chrome’s components.

References

• Chrome Releases Blog
• Chromium Security Severity Guidelines