1 files changed, 9 insertions, 0 deletions
diff --git a/xpcom/io/nsLocalFileWin.cpp b/xpcom/io/nsLocalFileWin.cpp
index 66e2678075..5a72c750cb 100644
--- a/xpcom/io/nsLocalFileWin.cpp
+++ b/xpcom/io/nsLocalFileWin.cpp
@@ -45,6 +45,7 @@
 #include "prproces.h"
 #include "prlink.h"
 
+#include "mozilla/FilePreferences.h"
 #include "mozilla/Mutex.h"
 #include "SpecialSystemDirectory.h"
 
@@ -1166,6 +1167,10 @@ nsLocalFile::InitWithPath(const nsAString& aFilePath)
     return NS_ERROR_FILE_UNRECOGNIZED_PATH;
   }
 
+  if (FilePreferences::IsBlockedUNCPath(aFilePath)) {
+    return NS_ERROR_FILE_ACCESS_DENIED;
+  }
+
   if (secondChar != L':' && (secondChar != L'\\' || firstChar != L'\\')) {
     return NS_ERROR_FILE_UNRECOGNIZED_PATH;
   }
@@ -1976,6 +1981,10 @@ nsLocalFile::CopySingleFile(nsIFile* aSourceFile, nsIFile* aDestParent,
     dwCopyFlags |= COPY_FILE_NO_BUFFERING;
   }
 
+  if (FilePreferences::IsBlockedUNCPath(destPath)) {
+    return NS_ERROR_FILE_ACCESS_DENIED;
+  }
+
   if (!move) {
     copyOK = ::CopyFileExW(filePath.get(), destPath.get(), nullptr,
                            nullptr, nullptr, dwCopyFlags);