WinXP Pro(Gold) Insecure System Restore File Permissions

From: Makoto Shiotsuki (shioat_private)
Date: Fri Oct 04 2002 - 06:36:10 PDT

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    WinXP Pro(Gold) Insecure System Restore File Permissions
    
    On the Windows XP Professional(Gold), the "System Restore" files
    are not protected properly by NTFS ACL, so every local user can 
    access these important files.
    
    System Restore files are stored in the "System Volume Information" 
    directory, and this directory itself is well protected by ACL so 
    normal users can not access to System Restore files generally.
    But System Restore Directory, along with their sub-directories, 
    is not protected by NTFS ACL(everyone:full), so that, every local
    user can access to System Restore files by specifying the path 
    directly.
    
    You can find the path of the System Restore Directory by following
    command line.
    
     c:\> reg query "HKLM\System\CurrentControlSet\Control\BackupRestore
    \FilesNotToBackup" /v "System Restore"
    
    And then, you can cd to the System Restore Directory.
    
     (example)
     c:\> cd \System Volume Information\_restore{8716531F-212F-45F1-8BAA-
    FB69F0C7FAEF}
    
    Within Restore Point Directories(RP0, RP1, ...), you will find a
    directory called "snapshot" including registry hive data.
    
      _REGISTRY_MACHINE_SAM
      _REGISTRY_MACHINE_SECURITY
      _REGISTRY_MACHINE_SOFTWARE
      _REGISTRY_MACHINE_SYSTEM
      _REGISTRY_USER_.DEFAULT
      _REGISTRY_USER_NTUSER_S-1-5-18
      .....
    
    These hive files are also freely accessible by every local user.
    Malicious local user may modify SOFTWARE hive (ex. add evil Run
    registry entry) expecting the administrator to execute System Restore
    and the modification will take effect.
    
    This problem is fixed by applying Windows XP SP1.  But I couldn't
    find out this issue in the "List of Fixes".
    
    Makoto Shiotsuki
    



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