Vulnerabilities > CVE-2011-2041 - Permissions, Privileges, and Access Controls vulnerability in Cisco Anyconnect Secure Mobility Client
Attack vector
LOCAL Attack complexity
LOW Privileges required
NONE Confidentiality impact
COMPLETE Integrity impact
COMPLETE Availability impact
COMPLETE Summary
The Start Before Logon (SBL) functionality in Cisco AnyConnect Secure Mobility Client (formerly AnyConnect VPN Client) before 2.3.254 on Windows, and on Windows Mobile, allows local users to gain privileges via unspecified user-interface interaction, aka Bug ID CSCta40556.
Vulnerable Configurations
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Accessing, Modifying or Executing Executable Files An attack of this type exploits a system's configuration that allows an attacker to either directly access an executable file, for example through shell access; or in a possible worst case allows an attacker to upload a file and then execute it. Web servers, ftp servers, and message oriented middleware systems which have many integration points are particularly vulnerable, because both the programmers and the administrators must be in synch regarding the interfaces and the correct privileges for each interface.
- Leverage Executable Code in Non-Executable Files An attack of this type exploits a system's trust in configuration and resource files, when the executable loads the resource (such as an image file or configuration file) the attacker has modified the file to either execute malicious code directly or manipulate the target process (e.g. application server) to execute based on the malicious configuration parameters. Since systems are increasingly interrelated mashing up resources from local and remote sources the possibility of this attack occurring is high. The attack can be directed at a client system, such as causing buffer overrun through loading seemingly benign image files, as in Microsoft Security Bulletin MS04-028 where specially crafted JPEG files could cause a buffer overrun once loaded into the browser. Another example targets clients reading pdf files. In this case the attacker simply appends javascript to the end of a legitimate url for a pdf (http://www.gnucitizen.org/blog/danger-danger-danger/) http://path/to/pdf/file.pdf#whatever_name_you_want=javascript:your_code_here The client assumes that they are reading a pdf, but the attacker has modified the resource and loaded executable javascript into the client's browser process. The attack can also target server processes. The attacker edits the resource or configuration file, for example a web.xml file used to configure security permissions for a J2EE app server, adding role name "public" grants all users with the public role the ability to use the administration functionality. The server trusts its configuration file to be correct, but when they are manipulated, the attacker gains full control.
- Blue Boxing This type of attack against older telephone switches and trunks has been around for decades. A tone is sent by an adversary to impersonate a supervisor signal which has the effect of rerouting or usurping command of the line. While the US infrastructure proper may not contain widespread vulnerabilities to this type of attack, many companies are connected globally through call centers and business process outsourcing. These international systems may be operated in countries which have not upgraded Telco infrastructure and so are vulnerable to Blue boxing. Blue boxing is a result of failure on the part of the system to enforce strong authorization for administrative functions. While the infrastructure is different than standard current applications like web applications, there are historical lessons to be learned to upgrade the access control for administrative functions.
- Restful Privilege Elevation Rest uses standard HTTP (Get, Put, Delete) style permissions methods, but these are not necessarily correlated generally with back end programs. Strict interpretation of HTTP get methods means that these HTTP Get services should not be used to delete information on the server, but there is no access control mechanism to back up this logic. This means that unless the services are properly ACL'd and the application's service implementation are following these guidelines then an HTTP request can easily execute a delete or update on the server side. The attacker identifies a HTTP Get URL such as http://victimsite/updateOrder, which calls out to a program to update orders on a database or other resource. The URL is not idempotent so the request can be submitted multiple times by the attacker, additionally, the attacker may be able to exploit the URL published as a Get method that actually performs updates (instead of merely retrieving data). This may result in malicious or inadvertent altering of data on the server.
- Target Programs with Elevated Privileges This attack targets programs running with elevated privileges. The attacker would try to leverage a bug in the running program and get arbitrary code to execute with elevated privileges. For instance an attacker would look for programs that write to the system directories or registry keys (such as HKLM, which stores a number of critical Windows environment variables). These programs are typically running with elevated privileges and have usually not been designed with security in mind. Such programs are excellent exploit targets because they yield lots of power when they break. The malicious user try to execute its code at the same level as a privileged system call.
Nessus
| NASL family | Windows |
| NASL id | CISCO_ANYCONNECT_VPN_2_3_254.NASL |
| description | The version of Cisco AnyConnect Secure Mobility Client installed on the remote host is earlier than 2.3.254 and may have the following vulnerabilities : - When the client is obtained from the VPN headend using a web browser, a helper application performs the download and installation. This helper application does not verify the authenticity of the downloaded installer, which could allow an attacker to send malicious code to the user instead. Only versions prior to 2.3.185 are affected by this vulnerability. (CVE-2011-2039) - Unprivileged users can elevate to LocalSystem privileges by enabling the Start Before Logon feature and performing unspecified actions with the Cisco AnyConnect Secure Mobility client interface in the Windows logon screen. (CVE-2011-2041) |
| last seen | 2020-06-01 |
| modified | 2020-06-02 |
| plugin id | 54954 |
| published | 2011-06-03 |
| reporter | This script is Copyright (C) 2011-2018 Tenable Network Security, Inc. |
| source | https://www.tenable.com/plugins/nessus/54954 |
| title | Cisco AnyConnect Secure Mobility Client < 2.3.254 Multiple Vulnerabilities |
| code | |
Seebug
| bulletinFamily | exploit |
| description | Bugtraq ID: 48081,48087 CVE ID：CVE-2011-2039 CVE-2011-2040 CVE-2011-2041 Cisco AnyConnect Secure Mobility Client是思科公司提供的远端存取解决方案，是思科的下一代VPN客户端。 Cisco AnyConnect安全移动客户端存在如下漏洞： -任意程序执行漏洞(CVE-2011-2040) 当从VPN前端部署Cisco AnyConnect安全移动客户端时，会使用WEB浏览器向VPN前端初始化一个SSL连接。在用户登录后，浏览器会显示门户窗口，当用户点击"Start AnyConnect连接时，进程会开始下载Cisco AnyConnect安全移动客户端。此行为导致浏览器首先下载"helper"应用程序，用于辅助下载和执行实际的Cisco AnyConnect安全移动客户端。helper应用程序是一个Linux和MacOS X平台上的Java Applet或者windows平台上的Java Applet或是一个浏览器上的ActiveX插件。下载的Helper程序以WEB浏览器中初始站点上下文执行。然后Helper程序会从VPN前端下载程序并执行。 当从VPN前端配置客户端时Helper应用程序无法正确校验下载的Cisco AnyConnect安全移动客户端，攻击者可以创建恶意看起来像正常VPN WEB登录页面的WEB页，使用社会工程欺骗或其他漏洞诱使用户访问，允许攻击者提供任意可执行程序让helper应用程序下载并执行。 -本地特权提升(CVE-2011-2041) 在启用了”Start Before Logon“及在windows登录屏幕中能与Cisco AnyConnect安全移动客户端图形用户接口交互的系统上，非特权用户可以提升特权为LocalSystem。此漏洞只影响Windows平台，因为SBL不支持Linux和MacOS X客户端。 Cisco AnyConnect VPN Client 2.4.202 Cisco AnyConnect Secure Mobility Client 3.0 Cisco AnyConnect Secure Mobility Client 2.5 Cisco AnyConnect Secure Mobility Client 2.3 厂商解决方案 用户可参考如下供应商提供的安全公告获得补丁信息： http://www.cisco.com/en/US/products/products_security_advisory09186a0080b80123.shtml |
| id | SSV:20604 |
| last seen | 2017-11-19 |
| modified | 2011-06-04 |
| published | 2011-06-04 |
| reporter | Root |
| title | Cisco AnyConnect Secure Mobility Client任意代码执行及本地特权提升漏洞 |