backend/src/main/java/org/raddatz/familienarchiv/importing/MassImportService.java

@@ -56,9 +56,17 @@ public class MassImportService {
 
     public enum State { IDLE, RUNNING, DONE, FAILED }
 
+    public enum SkipReason {
+        INVALID_FILENAME_PATH_TRAVERSAL,
+        INVALID_PDF_SIGNATURE,
+        FILE_READ_ERROR,
+        ALREADY_EXISTS,
+        S3_UPLOAD_FAILED
+    }
+
     public record SkippedFile(
             @Schema(requiredMode = Schema.RequiredMode.REQUIRED) String filename,
-            @Schema(requiredMode = Schema.RequiredMode.REQUIRED) String reason
+            @Schema(requiredMode = Schema.RequiredMode.REQUIRED) SkipReason reason
     ) {}
 
     public record ImportStatus(
@@ -291,6 +299,11 @@ public class MassImportService {
             if (index.isBlank()) continue;
 
             String filename = index.contains(".") ? index : index + ".pdf";
+            if (!isValidImportFilename(filename)) {
+                log.warn("Skipping import row {}: filename rejected — {}", i, filename);
+                skippedFiles.add(new SkippedFile(filename, SkipReason.INVALID_FILENAME_PATH_TRAVERSAL));
+                continue;
+            }
             Optional<File> fileOnDisk = findFileRecursive(filename);
             if (fileOnDisk.isEmpty()) {
                 log.warn("Datei nicht gefunden, importiere nur Metadaten: {}", filename);
@@ -300,17 +313,17 @@ public class MassImportService {
                 try {
                     if (!isPdfMagicBytes(fileOnDisk.get())) {
                         log.warn("Überspringe {}: Datei beginnt nicht mit %PDF-Signatur", filename);
-                        skippedFiles.add(new SkippedFile(filename, "INVALID_PDF_SIGNATURE"));
+                        skippedFiles.add(new SkippedFile(filename, SkipReason.INVALID_PDF_SIGNATURE));
                         continue;
                     }
                 } catch (IOException e) {
                     log.error("Fehler beim Prüfen der Magic-Bytes für {}", filename, e);
-                    skippedFiles.add(new SkippedFile(filename, "FILE_READ_ERROR"));
+                    skippedFiles.add(new SkippedFile(filename, SkipReason.FILE_READ_ERROR));
                     continue;
                 }
             }
 
-            Optional<String> skipReason = importSingleDocument(cells, fileOnDisk, filename, index);
+            Optional<SkipReason> skipReason = importSingleDocument(cells, fileOnDisk, filename, index);
             if (skipReason.isPresent()) {
                 skippedFiles.add(new SkippedFile(filename, skipReason.get()));
             } else {
@@ -320,6 +333,23 @@ public class MassImportService {
         return new ProcessResult(processed, skippedFiles);
     }
 
+    private boolean isValidImportFilename(String filename) {
+        if (filename == null || filename.isBlank()) return false;
+        if (filename.contains("/")) return false;
+        if (filename.contains("\\")) return false;
+        if (filename.contains("∕")) return false;  // U+2215 DIVISION SLASH
+        if (filename.contains("／")) return false;  // U+FF0F FULLWIDTH SOLIDUS
+        if (filename.contains("⧵")) return false;  // U+29F5 REVERSE SOLIDUS OPERATOR
+        if (filename.contains("..")) return false;
+        if (filename.equals(".")) return false;
+        if (filename.contains("\0")) return false;
+        // Paths.get() is safe here on Linux for all inputs that passed the checks above;
+        // it may throw InvalidPathException for OS-specific illegal chars on Windows,
+        // but those are not reachable in production.
+        if (Paths.get(filename).isAbsolute()) return false;
+        return true;
+    }
+
     // package-private: Mockito spy in tests can override to inject IOException
     InputStream openFileStream(File file) throws IOException {
         return new FileInputStream(file);
@@ -342,11 +372,11 @@ public class MassImportService {
      * @return empty Optional on success; an Optional containing the skip reason on failure/skip.
      */
     @Transactional
-    protected Optional<String> importSingleDocument(List<String> cells, Optional<File> file, String originalFilename, String index) {
+    protected Optional<SkipReason> importSingleDocument(List<String> cells, Optional<File> file, String originalFilename, String index) {
         Optional<Document> existing = documentService.findByOriginalFilename(originalFilename);
         if (existing.isPresent() && existing.get().getStatus() != DocumentStatus.PLACEHOLDER) {
             log.info("Dokument {} existiert bereits, überspringe.", originalFilename);
-            return Optional.of("ALREADY_EXISTS");
+            return Optional.of(SkipReason.ALREADY_EXISTS);
         }
 
         String archiveBox    = getCell(cells, colBox);
@@ -382,7 +412,7 @@ public class MassImportService {
                 status = DocumentStatus.UPLOADED;
             } catch (Exception e) {
                 log.error("S3 Upload Fehler für {}", file.get().getName(), e);
-                return Optional.of("S3_UPLOAD_FAILED");
+                return Optional.of(SkipReason.S3_UPLOAD_FAILED);
             }
         }
 
@@ -460,11 +490,18 @@ public class MassImportService {
     }
 
     private Optional<File> findFileRecursive(String filename) {
-        try (Stream<Path> walk = Files.walk(Paths.get(importDir))) {
+        File baseDir = new File(importDir);
-            return walk.filter(p -> !Files.isDirectory(p))
+        try (Stream<Path> walk = Files.walk(baseDir.toPath())) {
+            Optional<Path> match = walk.filter(p -> !Files.isDirectory(p))
                     .filter(p -> p.getFileName().toString().equals(filename))
-                    .map(Path::toFile)
                     .findFirst();
+            if (match.isEmpty()) return Optional.empty();
+            File candidate = match.get().toFile();
+            String baseDirCanonical = baseDir.getCanonicalPath();
+            if (!candidate.getCanonicalPath().startsWith(baseDirCanonical + File.separator)) {
+                throw DomainException.internal(ErrorCode.INTERNAL_ERROR, "Path escape detected: " + candidate);
+            }
+            return Optional.of(candidate);
         } catch (IOException e) {
             return Optional.empty();
         }

backend/src/test/java/org/raddatz/familienarchiv/importing/MassImportServiceTest.java

@@ -154,10 +154,10 @@ class MassImportServiceTest {
                 .build();
         when(documentService.findByOriginalFilename("doc001.pdf")).thenReturn(Optional.of(existing));
 
-        Optional<String> result = service.importSingleDocument(minimalCells("doc001.pdf"), Optional.empty(), "doc001.pdf", "doc001");
+        Optional<MassImportService.SkipReason> result = service.importSingleDocument(minimalCells("doc001.pdf"), Optional.empty(), "doc001.pdf", "doc001");
 
         verify(documentService, never()).save(any());
-        assertThat(result).isPresent().contains("ALREADY_EXISTS");
+        assertThat(result).isPresent().contains(MassImportService.SkipReason.ALREADY_EXISTS);
     }
 
     // ─── importSingleDocument — already-exists guard fires before file I/O ─────
@@ -179,10 +179,10 @@ class MassImportServiceTest {
         byte[] pdfHeader = {0x25, 0x50, 0x44, 0x46, 0x2D}; // %PDF-
         Files.write(physicalFile, pdfHeader);
 
-        Optional<String> result = service.importSingleDocument(
+        Optional<MassImportService.SkipReason> result = service.importSingleDocument(
                 minimalCells("present.pdf"), Optional.of(physicalFile.toFile()), "present.pdf", "present");
 
-        assertThat(result).isPresent().contains("ALREADY_EXISTS");
+        assertThat(result).isPresent().contains(MassImportService.SkipReason.ALREADY_EXISTS);
         verify(s3Client, never()).putObject(any(PutObjectRequest.class), any(RequestBody.class));
         verify(documentService, never()).save(any());
     }
@@ -204,7 +204,7 @@ class MassImportServiceTest {
         assertThat(service.getStatus().skipped()).isEqualTo(1);
         assertThat(service.getStatus().skippedFiles())
                 .extracting(MassImportService.SkippedFile::filename, MassImportService.SkippedFile::reason)
-                .containsExactly(org.assertj.core.groups.Tuple.tuple("upload_fail.pdf", "S3_UPLOAD_FAILED"));
+                .containsExactly(org.assertj.core.groups.Tuple.tuple("upload_fail.pdf", MassImportService.SkipReason.S3_UPLOAD_FAILED));
     }
 
     @Test
@@ -223,7 +223,7 @@ class MassImportServiceTest {
         assertThat(service.getStatus().skipped()).isEqualTo(1);
         assertThat(service.getStatus().skippedFiles())
                 .extracting(MassImportService.SkippedFile::reason)
-                .containsExactly("ALREADY_EXISTS");
+                .containsExactly(MassImportService.SkipReason.ALREADY_EXISTS);
     }
 
     // ─── importSingleDocument — create new document (metadata only) ───────────
@@ -283,11 +283,11 @@ class MassImportServiceTest {
         doThrow(new RuntimeException("S3 error"))
                 .when(s3Client).putObject(any(PutObjectRequest.class), any(RequestBody.class));
 
-        Optional<String> result = service.importSingleDocument(
+        Optional<MassImportService.SkipReason> result = service.importSingleDocument(
                 minimalCells("fail.pdf"), Optional.of(tempFile.toFile()), "fail.pdf", "fail");
 
         verify(documentService, never()).save(any());
-        assertThat(result).isPresent().contains("S3_UPLOAD_FAILED");
+        assertThat(result).isPresent().contains(MassImportService.SkipReason.S3_UPLOAD_FAILED);
     }
 
     // ─── importSingleDocument — sender handling ───────────────────────────────
@@ -438,6 +438,110 @@ class MassImportServiceTest {
         verify(documentService).findByOriginalFilename("doc002.pdf");
     }
 
+    // ─── isValidImportFilename — security regression — do not remove ─────────
+
+    @Test
+    void isValidImportFilename_returnsFalse_whenFilenameIsNull() {
+        boolean result = ReflectionTestUtils.invokeMethod(service, "isValidImportFilename", (String) null);
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    void isValidImportFilename_returnsFalse_whenFilenameIsBlank() {
+        boolean result = ReflectionTestUtils.invokeMethod(service, "isValidImportFilename", "   ");
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    void isValidImportFilename_returnsFalse_whenFilenameContainsForwardSlash() {
+        boolean result = ReflectionTestUtils.invokeMethod(service, "isValidImportFilename", "etc/passwd");
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    void isValidImportFilename_returnsFalse_whenFilenameContainsBackslash() {
+        boolean result = ReflectionTestUtils.invokeMethod(service, "isValidImportFilename", "..\\etc\\passwd");
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    void isValidImportFilename_returnsFalse_whenFilenameContainsDotDot() {
+        boolean result = ReflectionTestUtils.invokeMethod(service, "isValidImportFilename", "doc..evil.pdf");
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    void isValidImportFilename_returnsFalse_whenFilenameIsDotDot() {
+        boolean result = ReflectionTestUtils.invokeMethod(service, "isValidImportFilename", "..");
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    void isValidImportFilename_returnsFalse_whenFilenameIsAbsolutePath() {
+        boolean result = ReflectionTestUtils.invokeMethod(service, "isValidImportFilename", "/etc/passwd");
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    void isValidImportFilename_returnsFalse_whenFilenameContainsNullByte() {
+        boolean result = ReflectionTestUtils.invokeMethod(service, "isValidImportFilename", "file\0.pdf");
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    void isValidImportFilename_returnsTrue_whenFilenameIsPlainBasename() {
+        boolean result = ReflectionTestUtils.invokeMethod(service, "isValidImportFilename", "document.pdf");
+        assertThat(result).isTrue();
+    }
+
+    @Test
+    void isValidImportFilename_returnsFalse_whenFilenameContainsUnicodeDivisionSlash() {
+        boolean result = ReflectionTestUtils.invokeMethod(service, "isValidImportFilename", "foo∕bar.pdf");
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    void isValidImportFilename_returnsFalse_whenFilenameContainsFullwidthSlash() {
+        boolean result = ReflectionTestUtils.invokeMethod(service, "isValidImportFilename", "foo／bar.pdf");
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    void isValidImportFilename_returnsFalse_whenFilenameContainsUnicodeReverseSolidus() {
+        boolean result = ReflectionTestUtils.invokeMethod(service, "isValidImportFilename", "foo⧵bar.pdf");
+        assertThat(result).isFalse();
+    }
+
+    @Test
+    void isValidImportFilename_returnsTrue_whenFilenameHasLeadingDot() {
+        boolean result = ReflectionTestUtils.invokeMethod(service, "isValidImportFilename", ".hidden.pdf");
+        assertThat(result).isTrue();
+    }
+
+    @Test
+    void isValidImportFilename_returnsTrue_whenFilenameHasSpaces() {
+        boolean result = ReflectionTestUtils.invokeMethod(service, "isValidImportFilename", "Brief an Oma.pdf");
+        assertThat(result).isTrue();
+    }
+
+    @Test
+    void processRows_skipsRowAndContinues_whenFilenameIsPathTraversal() {
+        when(documentService.findByOriginalFilename("legitimate.pdf")).thenReturn(Optional.empty());
+        when(documentService.save(any())).thenAnswer(inv -> inv.getArgument(0));
+
+        List<List<String>> rows = List.of(
+                List.of("header"),
+                minimalCells("../evil"),       // row 1: path traversal — should be skipped
+                minimalCells("legitimate.pdf") // row 2: valid — should be processed
+        );
+        MassImportService.ProcessResult result = ReflectionTestUtils.invokeMethod(service, "processRows", rows);
+
+        assertThat(result.processed()).isEqualTo(1);
+        assertThat(result.skippedFiles())
+                .extracting(MassImportService.SkippedFile::reason)
+                .containsExactly(MassImportService.SkipReason.INVALID_FILENAME_PATH_TRAVERSAL);
+    }
+
     // ─── importSingleDocument — non-blank optional fields ────────────────────
 
     @Test
@@ -651,7 +755,22 @@ class MassImportServiceTest {
         assertThat(spyService.getStatus().skipped()).isEqualTo(1);
         assertThat(spyService.getStatus().skippedFiles())
                 .extracting(MassImportService.SkippedFile::reason)
-                .containsExactly("FILE_READ_ERROR");
+                .containsExactly(MassImportService.SkipReason.FILE_READ_ERROR);
+    }
+
+    // ─── findFileRecursive — symlink escape security regression — do not remove ─
+
+    @Test
+    void findFileRecursive_throwsDomainException_whenSymlinkEscapesImportDir(
+            @TempDir Path importDirPath, @TempDir Path outsideDir) throws Exception {
+        Path outsideFile = outsideDir.resolve("secret.pdf");
+        Files.writeString(outsideFile, "sensitive content");
+        Files.createSymbolicLink(importDirPath.resolve("secret.pdf"), outsideFile);
+
+        ReflectionTestUtils.setField(service, "importDir", importDirPath.toString());
+
+        assertThatThrownBy(() -> ReflectionTestUtils.invokeMethod(service, "findFileRecursive", "secret.pdf"))
+                .isInstanceOf(DomainException.class);
     }
 
     // ─── readOds — XXE security regression ───────────────────────────────────