发布时间 :1999-03-12 00:00:00
修订时间 :2008-09-09 08:34:26

[原文]The screen saver in Windows NT does not verify that its security context has been changed properly, allowing attackers to run programs with elevated privileges.

[CNNVD]Windows NT屏保权限许可和访问控制漏洞(CNNVD-199903-037)

        Windows NT的屏幕保护程序不能核实安全文件的正确修改。攻击者可以利用该漏洞提升权限运行程序。

- CVSS (基础分值)

CVSS分值: 7.2 [严重(HIGH)]
机密性影响: COMPLETE [完全的信息泄露导致所有系统文件暴露]
完整性影响: COMPLETE [系统完整性可被完全破坏]
可用性影响: COMPLETE [可能导致系统完全宕机]
攻击复杂度: LOW [漏洞利用没有访问限制 ]
攻击向量: LOCAL [漏洞利用需要具有物理访问权限或本地帐户]
身份认证: NONE [漏洞利用无需身份认证]

- CPE (受影响的平台与产品)

cpe:/o:microsoft:windows_nt:3.5.1:sp4Microsoft Windows NT 3.5.1 SP4
cpe:/o:microsoft:windows_nt:4.0:sp3Microsoft Windows 4.0 sp3
cpe:/o:microsoft:windows_nt:4.0:sp1Microsoft Windows 4.0 sp1
cpe:/o:microsoft:windows_nt:4.0:sp4Microsoft Windows 4.0 sp4
cpe:/o:microsoft:windows_nt:4.0Microsoft Windows NT 4.0
cpe:/o:microsoft:windows_nt:3.5.1:sp3Microsoft Windows NT 3.5.1 SP3
cpe:/o:microsoft:windows_nt:3.5.1:sp2Microsoft Windows NT 3.5.1 SP2
cpe:/o:microsoft:windows_nt:4.0:sp2Microsoft Windows 4.0 sp2
cpe:/o:microsoft:windows_nt:3.5.1:sp5Microsoft Windows NT 3.5.1 SP5
cpe:/o:microsoft:windows_nt:3.5.1:sp1Microsoft Windows NT 3.5.1 SP1

- OVAL (用于检测的技术细节)


- 官方数据库链接
(官方数据源) MITRE
(官方数据源) NVD
(官方数据源) CNNVD

- 其它链接及资源
(UNKNOWN)  MS  MS99-008

- 漏洞信息

Windows NT屏保权限许可和访问控制漏洞
高危 未知
1999-03-12 00:00:00 2006-04-19 00:00:00
        Windows NT的屏幕保护程序不能核实安全文件的正确修改。攻击者可以利用该漏洞提升权限运行程序。

- 公告与补丁


- 漏洞信息 (19359)

Microsoft Windows NT 4.0/SP1/SP2/SP3/SP4,Windows NT 3.5.1/SP1/SP2/SP3/SP4/SP5 Screensaver Vulnerability (EDBID:19359)
windows local
1999-03-10 Verified
0 Cybermedia Software Private Limited
N/A [点击下载]

When the computer is idle for the set time period (user definable) Winlogon.exe starts the screensaver. The screen saver process is selectable by the user. Winlogon.exe uses the CreateProcessAPI call to start the screen saver and immediately suspends it. At this point the screen saver is running with the security context of Winlogon.exe (system). Winlogon obtains the process handle, changes the primary security token of the screen saver to match the current user, and resumes the screen saver. Winlogon never verifies that the token change was successful. Therefore, a user could create an executable, set it as the screen saver, and should the security change fail it will run with full system-level privileges. 

This exploit and description provided by Cybermedia Software Private Limited.

The simulation consists of one 32-bit application say BEADMIN.EXE and one MS-DOS based application, say SCRNSAVE.EXE. The BEADMIN.EXE when started does the following Creates one event in â??not-signalâ??ed state Sets up the screen saver. The screen saver executable is specified as SCRNSAVE.EXE and the timeout is set to minimum. . BEADMIN.EXE now waits on the event. After some time, the screen saver is triggered. This results in Winlogon.Exe spawning SCRNSAVE.EXE. Since the CreateProcess call returns junk handle to Winlogon.Exe, the setting of primary token fails. Hence the SCRNSAVE.EXE application (NTVDM.EXE) runs in System Context. This SCRNSAVE.EXE again spawns BEADMIN.EXE application. Now this second copy of BEADMIN.EXE inherits the security context of NTVDM which is System Context. This application adds the logged in user to admin group and signals the event on which first instance of BEADMIN.EXE is waiting. In response to this the first copy of BEADMIN.EXE resets back the Screen Saver settings and quits. The logged in user name is passed between the first and second copy of BEADMIN.EXE using shared section.		

- 漏洞信息

Microsoft Windows NT Screensaver Context Local Privilege Escalation
Local Access Required Misconfiguration
Loss of Integrity
Exploit Public

- 漏洞描述

- 时间线

1999-03-10 Unknow
1999-03-10 Unknow

- 解决方案


Unknown or Incomplete

- 相关参考

- 漏洞作者

Unknown or Incomplete