Title: Microsoft Windows NT CSRSS Memory Access Violation Vulnerability
Severity: LOW
Description:
CSRSS.EXE is the Windows NT Client Server Run-time Subsystem. It is responsible for console windows and the creation and deletion of threads. The Windows NT kernel is dependant on this service and will halt if the service stops for any reason.
If certain combinations of special "whitespace" characters followed by "backspace" characters are output in high-level console I/O, a user could successfully crash a Windows NT, 2000 or XP system.
A small program similar to the following could exploit this issue:
while (1)
printf("\t\t\b\b\b\b\b\b");
The "backspace" character can be improperly handled by the CSRSS service when it is at the beginning of the console buffer. This issue is easiest to exploit using "tab" and "backspace" characters because several character cells, and therefore several memory locations, are all being accessed and written to at once. This allows the "backspace" character to potentially escape the console's buffer space and a "tab" character to overwrite the contents of memory belonging to the CSRSS process, but outside of the console buffer. This will cause the CSRSS process to terminate abnormally, causing the NT kernel to halt.
It is important to note that only programs using high-level console I/O such as C, C++, VBScript, perl, and REXX. It can not be induced using programs that use low-level I/O such as Cygwin and QBASIC.
Affected Products:
- Avaya DefinityOne Media Servers
- Avaya IP600 Media Servers
- Avaya S3400 Message Application Server
- Avaya S8100 Media Servers
- Microsoft Windows 2000 Advanced Server
- Microsoft Windows 2000 Advanced Server SP1
- Microsoft Windows 2000 Advanced Server SP2
- Microsoft Windows 2000 Datacenter Server
- Microsoft Windows 2000 Datacenter Server SP1
- Microsoft Windows 2000 Datacenter Server SP2
- Microsoft Windows 2000 Professional
- Microsoft Windows 2000 Professional SP1
- Microsoft Windows 2000 Professional SP2
- Microsoft Windows 2000 Server
- Microsoft Windows 2000 Server SP1
- Microsoft Windows 2000 Server SP2
- Microsoft Windows NT 3.5
- Microsoft Windows NT 3.5.1
- Microsoft Windows NT 3.5.1 SP1
- Microsoft Windows NT 3.5.1 SP2
- Microsoft Windows NT 3.5.1 SP3
- Microsoft Windows NT 3.5.1 SP4
- Microsoft Windows NT 3.5.1 SP5
- Microsoft Windows NT Enterprise Server 4.0
- Microsoft Windows NT Enterprise Server 4.0 SP1
- Microsoft Windows NT Enterprise Server 4.0 SP2
- Microsoft Windows NT Enterprise Server 4.0 SP3
- Microsoft Windows NT Enterprise Server 4.0 SP4
- Microsoft Windows NT Enterprise Server 4.0 SP5
- Microsoft Windows NT Enterprise Server 4.0 SP6
- Microsoft Windows NT Enterprise Server 4.0 SP6a
- Microsoft Windows NT Server 4.0
- Microsoft Windows NT Server 4.0 SP1
- Microsoft Windows NT Server 4.0 SP2
- Microsoft Windows NT Server 4.0 SP3
- Microsoft Windows NT Server 4.0 SP4
- Microsoft Windows NT Server 4.0 SP5
- Microsoft Windows NT Server 4.0 SP6
- Microsoft Windows NT Server 4.0 SP6a
- Microsoft Windows NT Terminal Server 4.0
- Microsoft Windows NT Terminal Server 4.0 SP1
- Microsoft Windows NT Terminal Server 4.0 SP2
- Microsoft Windows NT Terminal Server 4.0 SP3
- Microsoft Windows NT Terminal Server 4.0 SP4
- Microsoft Windows NT Terminal Server 4.0 SP5
- Microsoft Windows NT Terminal Server 4.0 SP6
- Microsoft Windows NT Workstation 4.0
- Microsoft Windows NT Workstation 4.0 SP1
- Microsoft Windows NT Workstation 4.0 SP2
- Microsoft Windows NT Workstation 4.0 SP3
- Microsoft Windows NT Workstation 4.0 SP4
- Microsoft Windows NT Workstation 4.0 SP5
- Microsoft Windows NT Workstation 4.0 SP6
- Microsoft Windows NT Workstation 4.0 SP6a
- Microsoft Windows XP Home
- Microsoft Windows XP Professional
References:
- Jonathan de Boyne Pollard: The CSRSS Backspace Bug in Windows NT 4/2000/XP.
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