Introduction: Heap Buffer Overflow in WebSQL

A recent security vulnerability, identified as CVE-2022-3446, has been discovered in Google Chrome versions prior to 106..5249.119. A heap buffer overflow in WebSQL, which could allow remote attackers to exploit heap corruption vulnerabilities and execute arbitrary code on the affected system. In this long-read post, we'll go over the details of this vulnerability, walk through a code snippet, provide links to the initial advisories, and share additional insights on the threat and potential mitigations.

Description: How the Heap Buffer Overflow Works

A heap buffer overflow occurs when a program writes data outside the boundaries of a dynamically allocated memory region. In a programming context, memory management is crucial, and developers typically control the size and allocation of memory.

In this case, the vulnerability is found in the WebSQL implementation within Google Chrome. A remote attacker can create a specially crafted HTML page that, when visited by a victim user, triggers the heap buffer overflow and potentially allows the attacker to exploit heap corruption, execute arbitrary code, and infiltrate a victim's system.

Relevant Code Snippet

The following code snippet demonstrates a potential attack scenario using the WebSQL feature. The attacker sets up a specially crafted HTML page with a WebSQL database:

<!DOCTYPE html>
<html>
<head>
  <title>CVE-2022-3446 - WebSQL Heap Buffer Overflow Example</title>
</head>
<body>
  <h1>WebSQL Heap Buffer Overflow Test</h1>
  <script>
    let db = openDatabase('exploit', '1.', 'exploit_db', 2 * 1024 * 1024); 

    db.transaction(function (tx) { 
      tx.executeSql('CREATE TABLE IF NOT EXISTS test_table (id unique, value)');
      tx.executeSql('INSERT INTO test_table (id, value) VALUES (?, ?)', [1, "test"]);
    });

    db.transaction(function (tx) { 
      // Exploit: Construct the crafted SQL query
      let exploitQuery = 'SELECT * FROM test_table WHERE 1=1';

      tx.executeSql(exploitQuery, [], function(tx, results) {
        let len = results.rows.length, i;
        for (i = ; i < len; i++) {
          console.log(results.rows.item(i).value)
        }
      });
    });
  </script>
</body>
</html>

In this example, the attacker cleverly crafts the query and database size to trigger the heap buffer overflow vulnerability within the Chrome browser, and potentially execute arbitrary code on the target system.

Original Advisory and References

- Google Chrome Release Blog Post: https://chromereleases.googleblog.com/2023/01/stable-channel-update-for-desktop_97.html
- CVE Details: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-3446
- Chromium Bug Tracker: https://bugs.chromium.org/p/chromium/issues/detail?id=1308487

Exploit Details and Potential Impact

The heap buffer overflow in WebSQL opens up an avenue for attackers to carry out heap corruption attacks, potentially leading to arbitrary code execution, denial of service (crashing the affected application), or information disclosure (accessing sensitive data stored in memory).

Mitigation and Best Practices

To mitigate the impact of CVE-2022-3446, users are encouraged to update their Chrome installations to version 106..5249.119 or later. This should address the vulnerabilities within WebSQL and protect their systems from potential attacks.

In addition, users should practice good browsing hygiene, such as avoiding visits to untrusted and unfamiliar websites, and being cautious with email attachments and links from unknown sources.

Conclusion

CVE-2022-3446 demonstrates the importance of staying up-to-date with software updates and patches, as even widely used and trusted applications like Google Chrome can be vulnerable to security issues. By understanding the threat posed by this heap buffer overflow vulnerability and implementing recommended mitigations, users can better protect their systems and data from potential exploitation.

Timeline

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