🔒 fix: prevent path traversal in MetadataEngine subfolder generation

FileOrganizer.Tests/MetadataEngineTests.cs

@@ -0,0 +1,33 @@
+using System;
+using System.Reflection;
+using FileOrganizer.Engines;
+using Xunit;
+
+namespace FileOrganizer.Tests
+{
+    public class MetadataEngineTests
+    {
+        private readonly MetadataEngine _engine = new MetadataEngine();
+
+        private string CallSanitizeForPath(string input)
+        {
+            var method = typeof(MetadataEngine).GetMethod("SanitizeForPath", BindingFlags.NonPublic | BindingFlags.Instance);
+            return (string)method.Invoke(_engine, new object[] { input });
+        }
+
+        [Theory]
+        [InlineData("ValidName", "ValidName")]
+        [InlineData("  TrimmedName  ", "TrimmedName")]
+        [InlineData("Name/With/Slash", "NameWithSlash")]
+        [InlineData("Name\\With\\Backslash", "NameWithBackslash")]
+        [InlineData("..", "Unknown")]
+        [InlineData("../etc/passwd", "etcpasswd")]
+        [InlineData(".", "Unknown")]
+        [InlineData("valid.name", "validname")]
+        public void SanitizeForPath_RemovesInvalidAndPathTraversalChars(string input, string expected)
+        {
+            string actual = CallSanitizeForPath(input);
+            Assert.Equal(expected, actual);
+        }
+    }
+}

FileOrganizer/Engines/MetadataEngine.cs

@@ -130,10 +130,14 @@ private string GetImageSubFolder(string filePath)
         private string SanitizeForPath(string folderName)
         {
             folderName = folderName.Trim();
+            // Remove invalid characters for a file name
             foreach (char c in Path.GetInvalidFileNameChars())
             {
                 folderName = folderName.Replace(c.ToString(), "");
             }
+            // Remove dots to prevent path traversal (e.g., ".." or ".")
+            folderName = folderName.Replace(".", "");
+
             return folderName.Length > 0 ? folderName : "Unknown";
         }
     }