On October 2022, security researchers revealed CVE-2022-3446, a serious flaw affecting Google Chrome's WebSQL implementation. WebSQL is an old database feature in browsers, and this specific vulnerability let attackers use a specially crafted HTML page to corrupt memory in Chrome. This post breaks down how the bug works, includes code snippets, and explains how an attacker could use it in a real-world exploit—all in clear, straightforward language.

What is CVE-2022-3446?

CVE-2022-3446 is a *heap buffer overflow* in the WebSQL component of Google Chrome. It affects browser versions prior to 106..5249.119, allowing remote attackers to exploit heap corruption by luring users to visit a malicious website.

Official references

- Google Chrome 106..5249.119 Release Notes
- Chromium Security Advisory

Understanding Heap Buffer Overflows (Quick Refresher)

A *heap buffer overflow* happens when a program writes more data to a block of memory (the "heap") than it should. This can overwrite other information, causing crashes, unexpected behavior, or sometimes allowing attackers to run their own code.

The Root Cause

The vulnerability lived in the way Chrome handled SQLite calls within WebSQL. When a website interacted with a WebSQL database using a specially crafted SQL statement, Chrome's C++ code didn't properly check the length of data being copied. This allowed data to overflow the intended buffer in heap memory.

Culprit (Pseudocode Style)

void DoSensitiveWebSQLFunction(const char* userInput, size_t len) {
    char buffer[100];
    // Dangerous: Copies too much from userInput into buffer.
    memcpy(buffer, userInput, len); // No check if len > 100!
    // ... do more stuff ...
}

If len comes from untrusted input (attacker-controlled SQL), and is more than 100, this will overwrite memory.

Suppose an attacker creates a HTML page that does something like this

<!DOCTYPE html>
<html>
  <body>
    <script>
      // Open a WebSQL database
      let db = openDatabase('testdb', '1.', 'Test', 2 * 1024 * 1024);

      // Craft a long string meant to overflow an internal buffer
      let evilPayload = 'A'.repeat(500); // Longer than the buffer

      db.transaction(function(tx) {
        // The dangerous statement
        tx.executeSql(SELECT &#039;${evilPayload}&#039;, [], function(tx, result) {
            console.log('Query ran (should not crash)');
        }, function(tx, error) {
            console.log('Error:', error);
        });
      });
    </script>
  </body>
</html>

If you open this page in a version of Chrome before 106..5249.119, the browser may crash or behave unpredictably.

Crash the Browser – Lead to denial of service (DoS).

2. Corrupt Heap Metadata – Allow the attacker to tamper with the memory allocator, potentially gaining code execution (RCE).
3. Escape the Sandbox – Make it easier to attack other processes or escape browser “sandboxing”.

If you use Google Chrome older than 106..5249.119, you are at risk.

- Chromium-based browsers like Microsoft Edge, Opera, and others may be affected if not updated.

Check your version:
Go to chrome://settings/help or Menu > Help > About Google Chrome

Developers patched the function to properly check the buffer length, preventing overflows

void DoSensitiveWebSQLFunction(const char* userInput, size_t len) {
    char buffer[100];
    if (len > sizeof(buffer)) len = sizeof(buffer); // Fix: Clamp length!
    memcpy(buffer, userInput, len); // Safe now
    // ... do more stuff ...
}

Patch information:
https://chromium.googlesource.com/chromium/src/+/e5fa4111e49156cbec2a899b1642f7e99aa1c5f

More Information and References

- CVE-2022-3446 at NVD
- Chromium Issue 1358936
- Patch Commit

Final Thoughts

CVE-2022-3446 is a typical example of why memory safety bugs are still a huge problem on the web. Keeping your browser up to date and being cautious about what sites you visit is always smart. WebSQL is old—but legacy features can still be risky!

If you're a developer, double-check all code paths handling external data, especially when dealing with memory or older technologies!

Timeline

Published on: 11/09/2022 19:15:00 UTC
Last modified on: 11/10/2022 15:23:00 UTC