diff --git a/upload/web/picupload_action.php b/upload/web/picupload_action.php
index f923ca5..73d74ac 100644
--- a/upload/web/picupload_action.php
+++ b/upload/web/picupload_action.php
@@ -1,44 +1,122 @@
 <?php
 
-// 允许上传的图片后缀
-$allowedExts = array("jpeg", "jpg", "png", "gif", "webp", "JPG", "PNG", "JPEG", "WEBP", "GIF", "bmp", "BMP", "tif", "tiff", "TIF", "TIFF", "ICO");
-$temp = explode(".", $_FILES["file"]["name"]);
-$extension = end($temp);        // 获取文件后缀名
-if ((($_FILES["file"]["type"] == "image/jpeg")
-|| ($_FILES["file"]["type"] == "image/jpg")
-|| ($_FILES["file"]["type"] == "image/tiff")
-|| ($_FILES["file"]["type"] == "image/gif")
-|| ($_FILES["file"]["type"] == "image/pjpeg")
-|| ($_FILES["file"]["type"] == "image/x-png")
-|| ($_FILES["file"]["type"] == "image/png")
-|| ($_FILES["file"]["type"] == "image/bmp")
-|| ($_FILES["file"]["type"] == "image/webp")
-|| ($_FILES["file"]["type"] == "image/x-icon"))
-&& ($_FILES["file"]["size"] < 3072000)    // 小于 3MB
-&& in_array($extension, $allowedExts))
+const UPLOAD_DIR = __DIR__ . '/../web/picupload/';
+const MAX_FILE_SIZE_BYTES = 3 * 1024 * 1024; // 3 MB
+
+const ALLOWED_MIME_TYPES = [
+    'image/jpeg',
+    'image/pjpeg', // Common for IE
+    'image/jpg',
+    'image/png',
+    'image/x-png', // Common for IE
+    'image/gif',
+    'image/webp',
+    'image/bmp',
+    'image/tiff',
+    'image/x-icon' // For .ico files
+];
+
+const ALLOWED_EXTENSIONS = [
+    'jpeg', 'jpg', 'png', 'gif', 'webp', 'bmp', 'tif', 'tiff', 'ico'
+];
+
+function handleUploadError(string $userMessage, string $logMessage = ''): void
 {
-    if ($_FILES["file"]["error"] > 0)
-    {
-        echo "错误：: " . $_FILES["file"]["error"] . "<br>";
+    if (!empty($logMessage)) {
+        error_log("Upload Error: " . $logMessage);
     }
-    else
-    {
-        $picpos = "picupload/" .mt_rand(100000000,999999999).".".$extension/*. $_FILES["file"]["name"]*/;
-        move_uploaded_file($_FILES["file"]["tmp_name"], $picpos);
-        echo "上传文件名: " . $_FILES["file"]["name"] . "<br>";
-        //echo "文件类型: " . $_FILES["file"]["type"] . "<br>";
-        echo "文件大小: " . ($_FILES["file"]["size"] / 1024) . " kB<br>";
-        //$resfile = "./picupload/tmp/_uploadres_tmp".mt_rand(1000,9999).".txt";
-        //echo "文件临时存储的位置: " . $_FILES["file"]["tmp_name"];
-        $cmd="/usr/bin/python /www/wwwroot/landchat/web/web_picupload.py /www/wwwroot/landchat/web/".$picpos;
-        echo '<div style="align:center;"><img src="https://img.zcool.cn/community/012b3c599276cc0000002129ebff53.gif"></div>';
-        echo '<script>if(typeof(Storage) !== "undefined") {window.location.replace(\'./picupload_res.php?cr=\'+localStorage.currentcr+\'&c='.$cmd.'\');}else{alert(\'不支持本地存储或没有打开过LandChat主页，无法上传!\')}</script>';
-        //echo "文件存储位置：".$picpos."<br>";
-        //echo "上传结果：<br>".$urlrsp."<br>";
+    echo "<h3>上传失败！</h3><p>$userMessage</p>";
+    exit;
+}
+
+// Initial file upload check
+if (!isset($_FILES['file']) || $_FILES['file']['error'] === UPLOAD_ERR_NO_FILE) {
+    handleUploadError("未选择文件。", "No file uploaded by user.");
+}
+
+// Check for common PHP upload errors
+if ($_FILES['file']['error'] > 0) {
+    $phpErrorMessage = match ($_FILES['file']['error']) {
+        UPLOAD_ERR_INI_SIZE => "文件大小超出服务器配置限制。",
+        UPLOAD_ERR_FORM_SIZE => "文件大小超出表单限制。",
+        UPLOAD_ERR_PARTIAL => "文件部分上传。",
+        UPLOAD_ERR_NO_TMP_DIR => "服务器临时文件夹缺失。",
+        UPLOAD_ERR_CANT_WRITE => "文件写入磁盘失败。",
+        UPLOAD_ERR_EXTENSION => "PHP扩展阻止文件上传。",
+        default => "发生未知上传错误。"
+    };
+    handleUploadError("上传失败: " . $phpErrorMessage, "PHP upload error code: " . $_FILES['file']['error'] . " for " . $_FILES['file']['name']);
+}
+
+// File size validation
+if ($_FILES['file']['size'] > MAX_FILE_SIZE_BYTES) {
+    handleUploadError(
+        "文件大小超出 " . (MAX_FILE_SIZE_BYTES / 1024 / 1024) . "MB 限制。",
+        "File size " . $_FILES['file']['size'] . " bytes exceeds " . MAX_FILE_SIZE_BYTES . " bytes."
+    );
+}
+
+// File extension validation
+$file_extension = strtolower(pathinfo($_FILES['file']['name'], PATHINFO_EXTENSION));
+if (!in_array($file_extension, ALLOWED_EXTENSIONS)) {
+    handleUploadError(
+        "非法的文件格式。允许的后缀有: " . implode(', ', ALLOWED_EXTENSIONS) . "。",
+        "Invalid file extension: " . $file_extension . " for " . $_FILES['file']['name']
+    );
+}
+
+// This checks the actual content of the file, not just the client-provided type
+$finfo = finfo_open(FILEINFO_MIME_TYPE);
+if ($finfo === false) {
+    handleUploadError("服务器无法验证文件类型。", "Failed to open fileinfo database.");
+}
+$real_mime_type = finfo_file($finfo, $_FILES['file']['tmp_name']);
+finfo_close($finfo);
+
+if (!in_array($real_mime_type, ALLOWED_MIME_TYPES)) {
+    handleUploadError(
+        "文件类型不被允许。",
+        "Invalid actual MIME type: " . $real_mime_type . " for " . $_FILES['file']['name']
+    );
+}
+
+// Ensure the target directory exists and is writable.
+if (!is_dir(UPLOAD_DIR)) {
+    if (!mkdir(UPLOAD_DIR, 0755, true)) {
+        handleUploadError("无法创建上传目录。", "Failed to create upload directory: " . UPLOAD_DIR);
     }
 }
-else
-{
-    echo "非法的文件格式或文件大于3MB限制";
+
+// Double-check if the directory is actually writable by the web server process
+if (!is_writable(UPLOAD_DIR)) {
+     handleUploadError("上传目录不可写。", "Upload directory not writable: " . UPLOAD_DIR);
 }
-?>
+
+// Generate a unique filename using a random number and the validated extension
+$unique_filename = mt_rand(100000000, 999999999) . '.' . $file_extension;
+$destination_path = UPLOAD_DIR . $unique_filename;
+
+// Move the uploaded file from its temporary location to the final destination
+if (!move_uploaded_file($_FILES['file']['tmp_name'], $destination_path)) {
+    handleUploadError(
+        "无法保存上传文件。",
+        "Failed to move uploaded file from " . $_FILES['file']['tmp_name'] . " to " . $destination_path
+    );
+}
+
+// Display user-friendly success messages
+echo "上传文件名: " . htmlspecialchars($_FILES["file"]["name"]) . "<br>";
+echo "文件大小: " . round($_FILES["file"]["size"] / 1024, 2) . " kB<br>"; // Display size in KB, rounded
+
+// Show animation to indicate processing
+echo '<div style="text-align:center;"><img src="https://img.zcool.cn/community/012b3c599276cc0000002129ebff53.gif" alt="Uploading..."></div>';
+
+echo '<script>
+    if (typeof(Storage) !== "undefined") {
+        var currentChatRoom = localStorage.currentcr || "";
+        window.location.replace("./picupload_res.php?cr=" + encodeURIComponent(currentChatRoom) + "&img=' . urlencode($unique_filename) . '");
+    } else {
+        alert("不支持本地存储或没有打开过LandChat主页，无法上传!");
+    }
+</script>';
+?>
\ No newline at end of file
diff --git a/upload/web/picupload_res.php b/upload/web/picupload_res.php
index 87193e5..1eef947 100644
--- a/upload/web/picupload_res.php
+++ b/upload/web/picupload_res.php
@@ -1,13 +1,36 @@
 <?php
-$rsp=shell_exec($_REQUEST['c']);
 
-if (strncmp($rsp, 'error', 5)==0) {
-    echo "<h3>上传失败！</h3>";
-    echo "<p>请向管理员求助，并附上调试信息：<b>【1. ".$_REQUEST['c']." 2. ".$rsp."】</b></p>";
+function displayUploadError(string $message): void
+{
+    echo "<h3>上传失败！</h3><p>$message</p>";
     exit;
-} else {
-    //echo "上传成功，正在把图片发送至聊天......";
 }
+
+if (!isset($_GET['img'])) {
+    displayUploadError("未指定图片文件。");
+}
+
+// Sanitize input
+$filename = basename(filter_var($_GET['img'], FILTER_SANITIZE_URL));
+$upload_base_dir = realpath(__DIR__ . '/../web/picupload/');
+$filepath = realpath($upload_base_dir . '/' . $filename);
+
+// Ensure the file exists AND its real path is strictly within the allowed upload directory.
+if ($filepath === false || strpos($filepath, $upload_base_dir) !== 0 || !file_exists($filepath)) {
+    displayUploadError("非法的图片文件或文件不存在。");
+}
+
+// Build the command safely
+$python_cmd = escapeshellcmd('/usr/bin/python');
+$script_arg = escapeshellarg(__DIR__ . '/web_picupload.py');
+$file_arg = escapeshellarg($filepath);
+
+$cmd = "$python_cmd $script_arg $file_arg";
+$rsp = shell_exec($cmd);
+if ($rsp === null) {
+    displayUploadError("执行脚本时发生错误。");
+}
+
 //上传
 require('./../config.php');
 date_default_timezone_set('PRC');