--- a/toolkit/components/maintenanceservice/workmonitor.cpp
+++ b/toolkit/components/maintenanceservice/workmonitor.cpp
@@ -42,18 +42,18 @@ BOOL PathGetSiblingFilePath(LPWSTR desti
  * @param  isApplying Out parameter for specifying if the status
  *         is set to applying or not.
  * @return TRUE if the information was filled.
 */
 static BOOL
 IsStatusApplying(LPCWSTR updateDirPath, BOOL &isApplying)
 {
   isApplying = FALSE;
-  WCHAR updateStatusFilePath[MAX_PATH + 1];
-  wcscpy(updateStatusFilePath, updateDirPath);
+  WCHAR updateStatusFilePath[MAX_PATH + 1] = {L'\0'};
+  wcsncpy(updateStatusFilePath, updateDirPath, MAX_PATH);
   if (!PathAppendSafe(updateStatusFilePath, L"update.status")) {
     LOG_WARN(("Could not append path for update.status file"));
     return FALSE;
   }
 
   nsAutoHandle statusFile(CreateFileW(updateStatusFilePath, GENERIC_READ,
                                       FILE_SHARE_READ | 
                                       FILE_SHARE_WRITE | 
@@ -97,22 +97,22 @@ IsUpdateBeingStaged(int argc, LPWSTR *ar
 /**
  * Gets the installation directory from the arguments passed to updater.exe.
  *
  * @param argcTmp    The argc value normally sent to updater.exe
  * @param argvTmp    The argv value normally sent to updater.exe
  * @param aResultDir Buffer to hold the installation directory.
  */
 static BOOL
-GetInstallationDir(int argcTmp, LPWSTR *argvTmp, WCHAR aResultDir[MAX_PATH])
+GetInstallationDir(int argcTmp, LPWSTR *argvTmp, WCHAR aResultDir[MAX_PATH + 1])
 {
   if (argcTmp < 2) {
     return FALSE;
   }
-  wcscpy(aResultDir, argvTmp[2]);
+  wcsncpy(aResultDir, argvTmp[2], MAX_PATH);
   WCHAR* backSlash = wcsrchr(aResultDir, L'\\');
   // Make sure that the path does not include trailing backslashes
   if (backSlash && (backSlash[1] == L'\0')) {
     *backSlash = L'\0';
   }
   bool backgroundUpdate = IsUpdateBeingStaged(argcTmp, argvTmp);
   bool replaceRequest = (argcTmp >= 4 && wcsstr(argvTmp[3], L"/replace"));
   if (backgroundUpdate || replaceRequest) {
@@ -299,17 +299,17 @@ ProcessSoftwareUpdateCommand(DWORD argc,
         !WriteStatusFailure(argv[1], 
                             SERVICE_NOT_ENOUGH_COMMAND_LINE_ARGS)) {
       LOG_WARN(("Could not write update.status service update failure.  (%d)",
                 GetLastError()));
     }
     return FALSE;
   }
 
-  WCHAR installDir[MAX_PATH] = {L'\0'};
+  WCHAR installDir[MAX_PATH + 1] = {L'\0'};
   if (!GetInstallationDir(argc, argv, installDir)) {
     LOG_WARN(("Could not get the installation directory"));
     if (!WriteStatusFailure(argv[1],
                             SERVICE_INSTALLDIR_ERROR)) {
       LOG_WARN(("Could not write update.status for GetInstallationDir failure."));
     }
     return FALSE;
   }