发布时间 :2001-05-03 00:00:00
修订时间 :2008-09-10 15:07:38

[原文]The i386_set_ldt system call in NetBSD 1.5 and earlier, and OpenBSD 2.8 and earlier, when the USER_LDT kernel option is enabled, does not validate a call gate target, which allows local users to gain root privileges by creating a segment call gate in the Local Descriptor Table (LDT) with a target that specifies an arbitrary kernel address.


        NetBSD 1.5及其早期版本,OpenBSD 2.8及其早期版本中的i386_set_ldt系统调用不验证调用门目标,当USER_LDT核心选项启用时,本地用户可以通过创建具有指定任意内核地址的目标的Local Descriptor Table (LDT)中的段调用门获取根权限。

- 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:openbsd:openbsd:2.8OpenBSD 2.8
cpe:/o:netbsd:netbsd:1.5NetBSD 1.5

- 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)  XF  user-ldt-validation(6222)
(UNKNOWN)  BID  2739
(UNKNOWN)  OPENBSD  20010302 The USER_LDT kernel option allows an attacker to gain access to privileged areas of kernel memory.
(UNKNOWN)  BUGTRAQ  20010219 Re: your mail

- 漏洞信息

高危 输入验证
2001-05-03 00:00:00 2006-11-14 00:00:00
        NetBSD 1.5及其早期版本,OpenBSD 2.8及其早期版本中的i386_set_ldt系统调用不验证调用门目标,当USER_LDT核心选项启用时,本地用户可以通过创建具有指定任意内核地址的目标的Local Descriptor Table (LDT)中的段调用门获取根权限。

- 公告与补丁

        NetBSD and Sun Microsystems have released patches which correct this vulnerability.
        NetBSD has released a kernel patch which may be applied to any of the 1.4x kernel series, as well as version 1.5.
        OpenBSD has released a kernel patch for version 2.8.
        It is possible to work around tihs vulnerability by building a kernel without the USER_LDT option enabled. In NetBSD it is enabled by default. To disable it, comment it out from the kernel configuration file and rebuild the kernel. If it has been enabled in OpenBSD, it can be disabled in the same manner. For the changes to take effect, both systems must be rebooted with the new kernel installed.
        After kernel patches have been installed, the kernel must be rebuilt and the system must be rebooted with the new version.
        Sun has released fix information for Solaris.
        The fixes for Solaris 7 and 8, x86 versions are available as of this writing. A fix for Solaris 2.6 x86 will be available June 18.
        Fixes for versions of Trusted Solaris are not yet available, but should be soon.
        The IDs of the Sun fixes are below.
        Sun Solaris 8_x86

  •         Sun 108529-07


        NetBSD NetBSD 1.4 x86
        NetBSD NetBSD 1.4.1 x86
        NetBSD NetBSD 1.4.2 x86
        Sun Solaris 2.6 _x86

  •         Sun 105182-27


        OpenBSD OpenBSD 2.8
        Sun Solaris 7.0 _x86

  •         Sun 106542-16


        Sun Trusted Solaris 7.0 x86

  •         Sun 109597-05


        Sun Trusted Solaris 8.0 x86

  •         Sun 110338-02


- 漏洞信息

Multiple BSD USER_LDT Kernel Option Memory Access
Local Access Required Input Manipulation
Loss of Integrity
Exploit Unknown

- 漏洞描述

NetBSD and OpenBSD contains a flaw that may allow a malicious user to gain access to unauthorized privileges. The issue is triggered when accessing kernel memory via a segment call gate when the USER_LDT kernel option is enabled, which may allow a malicious user to gain root privileges. This flaw may lead to a loss of integrity.

- 时间线

2001-02-16 Unknow
Unknow Unknow

- 解决方案

Currently, there are no known workarounds or upgrades to correct this issue. Consult your vendor for appropriate patches to address this vulnerability.

- 相关参考

- 漏洞作者