NT RAS Phonebook Buffer Overflow Vulnerability
BID:266
Info
NT RAS Phonebook Buffer Overflow Vulnerability
| Bugtraq ID: | 266 |
| Class: | Boundary Condition Error |
| CVE: | |
| Remote: | No |
| Local: | Yes |
| Published: | May 20 1999 12:00AM |
| Updated: | May 20 1999 12:00AM |
| Credit: | This vulnerability as published to BUGTRAQ by David Litchfield <[email protected]>. |
| Vulnerable: |
Microsoft Windows NT 4.0 SP5 Microsoft Windows NT 4.0 SP4 Microsoft Windows NT 4.0 SP3 Microsoft Windows NT 4.0 SP2 Microsoft Windows NT 4.0 SP1 Microsoft Windows NT 4.0 |
| Not Vulnerable: | |
Discussion
NT RAS Phonebook Buffer Overflow Vulnerability
Microsoft Windows NT RAS Service contains multiple buffer overflows that allow the execution of arbitrary code resulting in elevated privileges by local users.
The RAS Service allows users to dial and connect to RAS servers, or other dial-up servers. The RAS API function RasGetDialParams performs no bounds checkings which leads to an exploitable buffer overflow. The RAS RASMAN.EXE components implements the RAS Autodial Manager and RAS Connection Manager services which are used to dial out. RASMAN.EXE is a system process and is run in the security context of the LocalSystem account. RASMAN.EXE uses the RasGetDialParams function to read in things such as the telephone number from the Phonebook (rasphone.pbk) when is tries to dial out. This leads to a vulnerability that can be exploited by creating a phonebook entry with executable code inserted in the phone number parameter. If the phone number is over 299 bytes in length the process's saved return address will be overwritten.
Microsoft Windows NT RAS Service contains multiple buffer overflows that allow the execution of arbitrary code resulting in elevated privileges by local users.
The RAS Service allows users to dial and connect to RAS servers, or other dial-up servers. The RAS API function RasGetDialParams performs no bounds checkings which leads to an exploitable buffer overflow. The RAS RASMAN.EXE components implements the RAS Autodial Manager and RAS Connection Manager services which are used to dial out. RASMAN.EXE is a system process and is run in the security context of the LocalSystem account. RASMAN.EXE uses the RasGetDialParams function to read in things such as the telephone number from the Phonebook (rasphone.pbk) when is tries to dial out. This leads to a vulnerability that can be exploited by creating a phonebook entry with executable code inserted in the phone number parameter. If the phone number is over 299 bytes in length the process's saved return address will be overwritten.
Exploit / POC
Solution / Fix
NT RAS Phonebook Buffer Overflow Vulnerability
Solution:
Install the patches available at:
- ftp://ftp.microsoft.com/bussys/winnt/winnt-public/fixes/usa/NT40/hotfixes-postSP5/RAS-fix/
Solution:
Install the patches available at:
- ftp://ftp.microsoft.com/bussys/winnt/winnt-public/fixes/usa/NT40/hotfixes-postSP5/RAS-fix/
References
NT RAS Phonebook Buffer Overflow Vulnerability
References:
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