Vikunja has Path Traversal in CLI Restore

@@ -48,6 +48,19 @@ import (
 const maxConfigSize = 5 * 1024 * 1024    // 5 MB, should be largely enough
 const maxDumpEntrySize = 500 * 1024 * 1024 // 500 MB
 
+// parseDbFileName validates and extracts the table name from a database dump filename.
+// Returns the table name and true if valid, or empty string and false if invalid.
+func parseDbFileName(fname string) (string, bool) {
+	if !strings.HasSuffix(fname, ".json") {
+		return "", false
+	}
+	tableName := strings.TrimSuffix(fname, ".json")
+	if tableName == "" || strings.ContainsAny(tableName, "/\\") {
+		return "", false
+	}
+	return tableName, true
+}
+
 // Restore takes a zip file name and restores it
 func Restore(filename string, overrideConfig bool) error {
 
@@ -84,10 +97,11 @@ func Restore(filename string, overrideConfig bool) error {
 		}
 		if strings.HasPrefix(file.Name, "database/") {
 			fname := strings.TrimPrefix(file.Name, "database/")
-			if !strings.HasSuffix(fname, ".json") || len(fname) <= 5 {
+			tableName, valid := parseDbFileName(fname)
+			if !valid {
 				return fmt.Errorf("invalid database file name in zip archive: %q", file.Name)
 			}
-			dbfiles[fname[:len(fname)-5]] = file
+			dbfiles[tableName] = file
 			continue
 		}
 		if file.Name == ".env" {
@@ -166,6 +180,28 @@ func Restore(filename string, overrideConfig bool) error {
 
 	lastMigration := ms[len(ms)-2]
 
+	// Pre-validate all table data JSON before wiping to avoid leaving the database
+	// in a destroyed state when the archive contains corrupted table data.
+	for table, d := range dbfiles {
+		if table == "migration" {
+			continue
+		}
+		rc, err := d.Open()
+		if err != nil {
+			return fmt.Errorf("could not open table data for %s: %w", table, err)
+		}
+		var bufValidate bytes.Buffer
+		if _, err := bufValidate.ReadFrom(io.LimitReader(rc, maxDumpEntrySize)); err != nil {
+			rc.Close()
+			return fmt.Errorf("could not read table data for %s: %w", table, err)
+		}
+		rc.Close()
+		var test []map[string]interface{}
+		if err := json.Unmarshal(bufValidate.Bytes(), &test); err != nil {
+			return fmt.Errorf("invalid JSON in table data for %s: %w", table, err)
+		}
+	}
+
 	// Start by wiping everything - only after we've validated the archive
 	if err := db.WipeEverything(); err != nil {
 		return fmt.Errorf("could not wipe database: %w", err)