2 Commits
Author SHA1 Message Date
hoo2 3bdb2b0a6a Fix XSS by applying context-aware encoding 2026-01-11 15:40:59 +02:00
hoo2 34898059d9 Prepare XSS environment and XSS attack proof 2026-01-11 15:18:17 +02:00
5 changed files with 49 additions and 125 deletions
@@ -31,7 +31,7 @@ CREATE TABLE IF NOT EXISTS `login_users` (
) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
INSERT INTO `login_users` (`id`, `username`, `password`) VALUES
(1, 'u1', '$2y$10$L18u5/PyVkDgsce/DsUOQu0sKhTzh854Euhog3cVb1W4YAfgRzY8W'); /* php -r 'echo password_hash("p1", PASSWORD_DEFAULT), PHP_EOL;' */
(1, 'u1', 'p1');
CREATE TABLE IF NOT EXISTS `notes` (
`notesid` int(11) NOT NULL AUTO_INCREMENT,
+15 -58
View File
@@ -26,23 +26,12 @@ if(isset($_POST['new_website'], $_POST['new_username'], $_POST['new_password'])
$new_username = trim($_POST["new_username"]);
$new_password = trim($_POST["new_password"]);
// Insert new web site using a prepared statement to prevent SQL injection.
$sql_query = "INSERT INTO websites (login_user_id, web_url, web_username, web_password) VALUES " .
"((SELECT id FROM login_users WHERE username = ?), ?, ?, ?)";
$stmt = $conn->prepare($sql_query);
if ($stmt === false) {
$conn->close();
die("Prepare failed.");
}
$stmt->bind_param("ssss", $username, $new_website, $new_username, $new_password);
// Insert new web site
$sql_query = "INSERT INTO websites (login_user_id,web_url,web_username,web_password) VALUES " .
"((SELECT id FROM login_users WHERE username='{$username}'),'{$new_website}','{$new_username}','{$new_password}');";
//echo $sql_query;
$result = $stmt->execute();
$stmt->close();
$conn->close();
$result = $conn->query($sql_query);
$conn -> close();
// After processing, redirect to the same page to clear the form
unset($_POST['new_website']);
@@ -56,25 +45,11 @@ if(isset($_POST['new_website'], $_POST['new_username'], $_POST['new_password'])
if(isset($_POST['delete_website']) && trim($_POST["websiteid"] != '')) {
$webid = trim($_POST["websiteid"]);
// Cast to int to avoid unexpected input and use a prepared statement to prevent SQL injection.
$webid = (int)trim($_POST["websiteid"]);
// Delete selected web site
$sql_query = "DELETE FROM websites WHERE webid = ?";
$stmt = $conn->prepare($sql_query);
if ($stmt === false) {
$conn->close();
die("Prepare failed.");
}
$stmt->bind_param("i", $webid);
$sql_query = "DELETE FROM websites WHERE webid='{$webid}';";
//echo $sql_query;
$result = $stmt->execute();
$stmt->close();
$conn->close();
$result = $conn->query($sql_query);
$conn -> close();
// After processing, redirect to the same page to clear the form
unset($_POST['websiteid']);
@@ -82,40 +57,22 @@ if(isset($_POST['delete_website']) && trim($_POST["websiteid"] != '')) {
exit();
}
// Display list of user's web sites using a prepared statement to prevent SQL injection.
$sql_query = "SELECT * FROM websites INNER JOIN login_users ON websites.login_user_id=login_users.id WHERE login_users.username = ?";
// Display list of user's web sites
$sql_query = "SELECT * FROM websites INNER JOIN login_users ON websites.login_user_id=login_users.id WHERE login_users.username='{$username}';";
//echo $sql_query;
$stmt = $conn->prepare($sql_query);
if ($stmt === false) {
$conn->close();
die("Prepare failed.");
}
$stmt->bind_param("s", $username);
$stmt->execute();
$result = $stmt->get_result();
$stmt->close();
$result = $conn->query($sql_query);
//echo htmlspecialchars($username);
$safe_username = htmlspecialchars($username, ENT_QUOTES | ENT_SUBSTITUTE, "UTF-8");
echo "<h3>Entries of " . $safe_username . "</h3>";
echo "<h3>Entries of " . $username . "</h3>";
if (!empty($result) && $result->num_rows >= 1) {
while ($row = $result -> fetch_assoc()) {
// Escape output to prevent stored XSS (DB content must be treated as untrusted).
$safe_url = htmlspecialchars($row["web_url"], ENT_QUOTES | ENT_SUBSTITUTE, "UTF-8");
$safe_user = htmlspecialchars($row["web_username"], ENT_QUOTES | ENT_SUBSTITUTE, "UTF-8");
$safe_pass = htmlspecialchars($row["web_password"], ENT_QUOTES | ENT_SUBSTITUTE, "UTF-8");
$webid_safe = (int)$row["webid"];
echo "<table border=0>";
echo "<tr style='background-color: #f4f4f4;'><td colspan=2>" . $safe_url . "</td></tr>" .
"<tr><td>Username: " . $safe_user . "</td><td>Password: " . $safe_pass . "</td></tr>";
echo "<tr style='background-color: #f4f4f4;'><td colspan=2>" . $row["web_url"] . "</td></tr>" .
"<tr><td>Username: " . $row["web_username"] . "</td><td>Password: " . $row["web_password"] . "</td></tr>";
echo "<tr><td><form method='POST' style='height: 3px'>" .
"<input type='hidden' name='websiteid' value='" . $webid_safe . "'>" .
"<input type='hidden' name='websiteid' value='" . $row["webid"] . "'>" .
"<button type='submit' name='delete_website'>Delete</button></form></td></tr>";
echo "<tr><td colspan=2 style=height: 20px;></td></tr>";
+23 -28
View File
@@ -26,51 +26,46 @@ if ($_SERVER["REQUEST_METHOD"] === "POST") {
// }
require_once __DIR__ . "/config.php";
// Authentication with hashed passwords:
// 1) Fetch the stored hash by username
// SQL injection mitigation: use a prepared statement with bound parameters.
// User input is treated strictly as data, not as part of the SQL syntax.
// 2) Verify the submitted password with password_verify()
$stmt = $conn->prepare("SELECT id, password FROM login_users WHERE username = ?");
// SQL injection mitigation: use a prepared statement with bound parameters.
// User input is treated strictly as data, not as part of the SQL syntax.
$stmt = $conn->prepare("SELECT id FROM login_users WHERE username = ? AND password = ?");
if ($stmt === false) {
// Fail closed (do not leak details in production).
die("Prepare failed.");
}
$stmt->bind_param("s", $username);
$stmt->bind_param("ss", $username, $password);
$stmt->execute();
$result = $stmt->get_result(); // Requires mysqlnd (usually enabled)
$stmt->store_result(); // Needed to use $stmt->num_rows
unset($_POST['username']);
unset($_POST['password']);
if ($result && $result->num_rows === 1) {
$row = $result->fetch_assoc();
$stored_hash = $row["password"];
if ($stmt->num_rows >= 1) {
// Regenerate session ID to prevent session fixation!
//session_regenerate_id(true);
// Verify password against the stored hash.
if (password_verify($password, $stored_hash)) {
// Regenerate session ID to prevent session fixation!
//session_regenerate_id(true);
// Successfully logged in
$_SESSION['username'] = $username;
$_SESSION['loggedin'] = true;
// Successfully logged in
$_SESSION['username'] = $username;
$_SESSION['loggedin'] = true;
//while ($row = $result -> fetch_assoc()) {
// print_r($row);
// $_SESSION['user_id'] = $row['id'];
//}
$stmt->close();
$conn->close();
// Close
$stmt->close();
$conn -> close();
header("Location: dashboard.php");
exit;
} else {
$login_message = "Invalid username or password";
}
// Redirect to a dashboard page
header("Location: dashboard.php");
exit;
} else {
$login_message = "Invalid username or password";
}
$stmt->close();
$conn->close();
$conn -> close();
}
}
?>
+5 -16
View File
@@ -50,24 +50,13 @@ if(isset($_POST['new_note']) && trim($_POST['new_note']) !='') {
//$sql_query = "INSERT INTO notes (login_user_id,note) VALUES " .
// "((SELECT id FROM login_users WHERE username='{$username}'),('{$new_note}'));";
// Insert new note using a prepared statement to prevent SQL injection.
$sql_query = "INSERT INTO notes (login_user_id, note) ".
"VALUES ((SELECT id FROM login_users WHERE username = ?), ?)";
$sql_query = "INSERT INTO notes (login_user_id, note) ".
"VALUES ((SELECT id FROM login_users WHERE username='{$username}'), '{$new_note}')";
$stmt = $conn->prepare($sql_query);
if ($stmt === false) {
// Fail closed (do not leak DB details).
$conn->close();
die("Prepare failed.");
}
$stmt->bind_param("ss", $username, $new_note);
//echo $sql_query;
$result = $stmt->execute();
$stmt->close();
$conn->close();
//echo $sql_query;
$result = $conn->query($sql_query);
$conn -> close();
// After processing, redirect to the same page to clear the form
unset($_POST['new_note']);
+4 -21
View File
@@ -29,28 +29,11 @@ if ($_SERVER["REQUEST_METHOD"] === "POST") {
//}
require_once __DIR__ . "/config.php";
// Insert a new user using a prepared statement to prevent SQL injection.
$sql_query = "INSERT INTO login_users (username, password) VALUES (?, ?)";
$stmt = $conn->prepare($sql_query);
if ($stmt === false) {
$login_message = "Database error (prepare failed).";
$result = false;
} else {
// Hash the password before storing it.
// Never store login passwords in plaintext.
$password_hash = password_hash($new_password, PASSWORD_DEFAULT);
if ($password_hash === false) {
$login_message = "Password hashing failed.";
$result = false;
} else {
// Store the hash (not the plaintext password).
$stmt->bind_param("ss", $new_username, $password_hash);
$result = $stmt->execute();
}
$stmt->close();
}
// Insert a new user
$sql_query = "INSERT INTO login_users (username,password) VALUES ('{$new_username}','{$new_password}');";
//echo $sql_query;
$result = $conn->query($sql_query);
unset($_POST['new_username']);
unset($_POST['new_password']);