发布时间 :1999-03-30 00:00:00
修订时间 :2008-09-09 08:34:31

[原文]XFree86 xfs command is vulnerable to a symlink attack, allowing local users to create files in restricted directories, possibly allowing them to gain privileges or cause a denial of service.


        XFree86 xfs命令易受到符号链接攻击,本地用户可以利用该漏洞在受限目录下创建文件,也有可能获取权限或者导致服务拒绝。

- CVSS (基础分值)

CVSS分值: 7.5 [严重(HIGH)]
机密性影响: PARTIAL [很可能造成信息泄露]
完整性影响: PARTIAL [可能会导致系统文件被修改]
可用性影响: PARTIAL [可能会导致性能下降或中断资源访问]
攻击复杂度: LOW [漏洞利用没有访问限制 ]
攻击向量: [--]
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:netbsd:netbsd:1.3.3NetBSD 1.3.3
cpe:/o:debian:debian_linux:2.0Debian Debian Linux 2.0
cpe:/o:redhat:linux:5.1Red Hat Linux 5.1
cpe:/o:suse:suse_linux:5.3SuSE SuSE Linux 5.3
cpe:/o:debian:debian_linux:2.1Debian Debian Linux 2.1

- 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

- 漏洞信息

高危 其他
1999-03-30 00:00:00 2005-10-20 00:00:00
        XFree86 xfs命令易受到符号链接攻击,本地用户可以利用该漏洞在受限目录下创建文件,也有可能获取权限或者导致服务拒绝。

- 公告与补丁

        Upgrade to XFree86 The other related XFree86 symbolic link vulnerabilities are fixed in this version as well.

- 漏洞信息

XFree86 xfs /tmp/.font-unix Symlink Privilege Escalation
Local Access Required Race Condition
Loss of Confidentiality, Loss of Integrity, Loss of Availability
Exploit Public

- 漏洞描述

XFree86 xfs, the font server for the X Windowing system, contains a flaw that may allow a malicious user to overwrite the permissions of any file on the local system. The issue is triggered when root (or an appropriately privileged user) runs the xfs server after the attacker (a local user) creates a symlink from /tmp/.font-unix to any other file (such as /etc/shadow). It is possible that the flaw may allow information disclosure, privilege elevation or denial of service.

- 时间线

1999-03-29 Unknow
1999-03-29 Unknow

- 解决方案

Upgrade to version or higher, as it has been reported to fix this vulnerability. It is also possible to correct the flaw by implementing the following workarounds: 1) Do not run xfs as root or other priviliged user. 2) rm -rf /tmp/.font-unix before running xfs as a privileged user. 3) Apply the patch provided by Matthieu Herrb (see referenced security mail list post).

- 相关参考

- 漏洞作者

- 漏洞信息

Multiple Vendor xfs Symlink Vulnerability
Origin Validation Error 359
No Yes
1999-03-30 12:00:00 2009-07-11 12:16:00
First posted to BugTraq by Lukasz Trabinski <lukasz@LT.WSISIZ.EDU.PL> on March 30, 1999.

- 受影响的程序版本

S.u.S.E. Linux 5.3
RedHat Linux 5.1
- Standard & Poors ComStock 4.2.4
Pacific HiTech TurboLinux 1.2
NetBSD NetBSD 1.3.3
Debian Linux 2.1
Debian Linux 2.0 r5
Debian Linux 2.0
Caldera OpenLinux Standard 1.2

- 漏洞讨论

Xfs, the Xfree86 font server included with RedHat 5.1 is vulnerable to a /tmp symbolic link attack. Xfs creates a file in /tmp called .font-unix that will be followed if a symlink. Any file pointed to by the symbolic link will be overwritten.

- 漏洞利用

Currently the SecurityFocus staff are not aware of any exploits for this issue. If you feel we are in error or are aware of more recent information, please mail us at:

- 解决方案

Upgrade to XFree86 The other related XFree86 symbolic link vulnerabilities are fixed in this version as well.

- 相关参考