CVE-2022-31631 - SQL Injection Vulnerability in PHP PDO::quote() Function for SQLite

SQL injection vulnerabilities pose a significant risk to web applications, as they allow attackers to execute malicious SQL queries on the target database, gain unauthorized access to sensitive data, or even manipulate the affected system. CVE-2022-31631 is an SQL injection vulnerability discovered in PHP versions 8..* before 8..27, 8.1.* before 8.1.15, and 8.2.* before 8.2.2 that affects the PDO::quote() function when using it with SQLite. In this post, we will explore the details of this vulnerability, including its exploitation and potential impacts, and provide recommendations on how to mitigate it.

Vulnerability Details

CVE-2022-31631 is an SQL injection vulnerability affecting the PDO::quote() function in PHP. This function is commonly used to quote user-supplied data before passing it to an SQL query in order to prevent SQL injection attacks. However, supplying an overly long string to this function when using SQLite can cause the driver to incorrectly quote the data, which may further lead to SQL injection vulnerabilities.

The issue arises due to the incorrect handling of long strings by the SQLite library when using the PDO::quote() function. In some cases, the PDO SQLite driver incorrectly quotes the user-supplied data, allowing an attacker to craft a malicious SQL query and exploit the target system.

Here is a code snippet illustrating the use of PDO::quote() function

// Connect to the SQLite database using PDO
$pdo = new PDO('sqlite:/path/to/database.sqlite3');

// User-supplied data, which may contain malicious input
$user_data = $_POST['user_data'];

// Quote the input using PDO::quote() function
$quoted_data = $pdo->quote($user_data);

// Build the SQL query using the quoted data
$sql = "INSERT INTO example_table (data) VALUES ($quoted_data)";

// Execute the query
$pdo->exec($sql);

Exploit Details

An attacker can exploit the CVE-2022-31631 vulnerability by crafting a specially designed, overly long string that causes the PDO::quote() function to quote incorrectly. This could allow the attacker to inject malicious SQL code that, when executed, provides unauthorized access to sensitive data, modifies the database, or impacts the targeted system's actions.

Links to Original References

1. CVE Details: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-31631
2. PHP Changelog: https://www.php.net/ChangeLog-8.php

To mitigate the risks associated with CVE-2022-31631, it is recommended that affected users

1. Upgrade to PHP versions 8..27, 8.1.15, or 8.2.2 or later as soon as possible. These versions contain a fix for this vulnerability.

2. Properly validate and sanitize user-supplied data before passing it to any PHP function, such as the use of filter_var() function, or using prepared statements for building and executing SQL queries.

3. Regularly monitor security advisories and apply necessary patches timely to keep your systems protected.

Conclusion

CVE-2022-31631 is a significant SQL injection vulnerability in PHP, affecting the PDO::quote() function when using SQLite. By exploiting this vulnerability, attackers can execute malicious SQL queries and gain unauthorized access to sensitive data or manipulate the targeted system's actions. Users are advised to upgrade to the patched PHP versions and implement proper input validation and sanitization measures when handling user-supplied data to mitigate the risks associated with this vulnerability.

Timeline

Published on: 02/12/2025 22:15:29 UTC