Microsoft Windows Remote Desktop Protocol checksum information leak

win-rdp-checksum-leak (10121) The risk level is classified as LowLow Risk


Microsoft Windows 2000 and Windows XP using encrypted Remote Desktop Protocol (RDP) packets could allow a remote attacker to obtain sensitive information. If more than one packet with the same contents is sent twice, a vulnerability in the way RDP version 5.0 handles encrypted packets would cause the checksums for the packets to be identical, which could cause an information leak. This could allow an attacker using a network sniffing tool to monitor RDP traffic to and capture encrypted information. The attacker would then need to decrypt the traffic to obtain sensitive session information.


Obtain Information


Apply the appropriate patch for your system, as listed in Microsoft Security Bulletin MS02-051. See References.

For Windows 2000: Microsoft originally provided a patch for this vulnerability in MS02-051, but it has been superseded by the patch released with MS04-011. See References.


  • BugTraq Mailing List, Mon Sep 16 2002 - 03:52:00 CDT : Microsoft Windows Remote Desktop Protocol checksum and keystroke vulnerabilities.
  • Microsoft Security Bulletin MS02-051: Cryptographic Flaw in RDP Protocol can Lead to Information Disclosure (Q324380).
  • Microsoft Security Bulletin MS04-011: Security Update for Microsoft Windows (835732).
  • BID-5711: Microsoft Windows Encrypted RDP Packet Information Leakage Vulnerability
  • BID-5712: Microsoft Windows RDP Keystroke Injection Vulnerability
  • CVE-2002-0863: Remote Data Protocol (RDP) version 5.0 in Microsoft Windows 2000 and RDP 5.1 in Windows XP does not encrypt the checksums of plaintext session data, which could allow a remote attacker to determine the contents of encrypted sessions via sniffing, aka Weak Encryption in RDP Protocol.
  • OSVDB ID: 866: Cryptographic Info leak in RDP Protocol
  • US-CERT VU#865833: Microsoft Windows Remote Desktop Protocol (RDP) uses weak algorithm for encrypting packets

Platforms Affected:

  • Microsoft Windows 2000
  • Microsoft Windows XP


Sep 16, 2002

The information within this database may change without notice. Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. In no event shall the author/distributor (IBM Internet Security Systems X-Force) be held liable for any damages whatsoever arising out of or in connection with the use or spread of this information.

For corrections or additions please email ignore thisxforceignore this@ignore thisus.ignore thisibm.comignore this

Return to the main page