Windows Workstation Service NetrWkstaUserEnum Denial of Service
Secunia Advisory: SA23487 Release Date: 2006-12-26
Critical: Not critical
Where: From local network
Solution Status: Unpatched
Microsoft Windows 2000 Advanced Server
Microsoft Windows 2000 Datacenter Server
Microsoft Windows 2000 Professional
Microsoft Windows 2000 Server
Microsoft Windows XP Home Edition
Microsoft Windows XP Professional
h07 has discovered a weakness in Microsoft Windows, which can be exploited by malicious people to cause a DoS (Denial of Service).
The weakness is caused due to an error in the Workstation service when handling NetrWkstaUserEnum RPC requests with a large value in the maxlen field.
Successful exploitation causes svchost.exe to consume a large amount of memory and may result in the system becoming temporarily unresponsive.
The weakness is confirmed on a fully patched Windows XP SP2 system and has also been reported in Windows 2000 SP4.
Solution: Filter NetrWkstaUserEnum RPC requests with a large maxlen value.
Provided and/or discovered by: h07
Original Advisory: http://milw0rm.com/exploits/3013