ID

VAR-201106-0113

CVE

CVE-2011-2041

TITLE

Cisco AnyConnect Secure Mobility Client Vulnerability gained in

DESCRIPTION

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. The problem is Bug ID CSCta40556 It is a problem.Authority may be obtained by local users. Cisco AnyConnect Secure Mobility Client is a remote access solution from Cisco that is Cisco's next-generation VPN client. A local elevation of privilege vulnerability exists in the Cisco AnyConnect Secure Mobility Vulnerability. This vulnerability only affects the Windows platform because SBL does not support Linux and MacOS X clients. Local attackers can exploit this issue to gain elevated privileges. Successful exploits will result in the complete compromise of affected computers. Versions prior to AnyConnect Secure Mobility Client 2.3.254 are vulnerable. There are no workarounds for the vulnerabilities described in this advisory. The affected versions are included in the following table: +------------------------------------------------------------+ | Vulnerability | Platform | Affected Versions | |-------------------+-----------+----------------------------| | | Microsoft | All versions prior to | | | Windows | 2.3.185 | | |-----------+----------------------------| | Arbitrary Program | | * All versions in major | | Execution | | releases other than | | Vulnerability | Linux, | 2.5.x and 3.0.x. | | | Apple | * 2.5.x releases prior | | | MacOS X | to 2.5.3041 | | | | * 3.0.x releases prior | | | | to 3.0.629 | |-------------------+-----------+----------------------------| | | Microsoft | All versions prior to | | Local Privilege | Windows | 2.3.254 | |Escalation |-----------+----------------------------| | Vulnerability | Linux, | | | | Apple | Not affected | | | MacOS X | | +------------------------------------------------------------+ Note: Microsoft Windows Mobile versions are affected by the Arbitrary Program Execution Vulnerability. No other Cisco products are currently known to be affected by these vulnerabilities. This action causes the browser to first download a "helper" application that aids in downloading and executing the actual Cisco AnyConnect Secure Mobility Client. The helper application is a Java applet on the Linux and MacOS X platforms, and either a Java applet on the Windows platform or an ActiveX control if the browser is capable of utilizing ActiveX controls. The downloaded helper application is executed in the context of the originating site in the user's web browser. An attacker could create a malicious web page that looks like the normal VPN web login page and entice a user, through social engineering or exploitation of other vulnerabilities, to visit it. This would allow the attacker to supply an arbitrary executable that the helper application would download and execute on the machine of the affected user. This arbitrary executable would be executed with the same operating system privileges under which the web browser was run. Common Vulnerabilities and Exposures (CVE) IDs CVE-2011-2039 (for CSCsy00904) and CVE-2011-2040 (for CSCsy05934) have been assigned for these vulnerabilities. Additional Considerations for the Arbitrary Program Execution Vulnerability +------------------------------------------------------------ Note that while new versions of the ActiveX control and Java applet that are shipped with the Cisco AnyConnect Secure Mobility Client make use of code signing to validate the authenticity of components downloaded from the VPN headend, there is still the issue of old versions that do not validate downloaded components. An attacker may engineer a web page to supply an affected version of the ActiveX control or Java applet and still accomplish arbitrary program execution because of the lack of authenticity validation. Mitigating the risk of old versions of the ActiveX control can be accomplished in the following ways: * Load fixed Cisco AnyConnect Secure Mobility Client versions on the VPN headend and establish a VPN connection (via web browser or standalone client). This action will cause the new version of the Cisco AnyConnect Secure Mobility Client, including a new version of the ActiveX control to install. When this occurs, an old version of the ActiveX control will not be instantiated if one is presented for download. This action accomplishes the same result as the previous recommendation -- it deploys new, fixed versions of the ActiveX control so that old, vulnerable versions of the control are not instantiated if one is presented for download. This action prevents the ActiveX control from being instantiated under any scenario. Instructions for setting the kill bit are beyond the scope of this document; refer to the Microsoft Support article "How to stop an ActiveX control from running in Internet Explorer" at http://support.microsoft.com/kb/240797 and the Microsoft Security Vulnerability Research & Defense's "Kill-Bit FAQ" blog posts referenced in the Microsoft Support article for more information. Note that this CLSID did not change with new versions of the ActiveX control that implement code signing validation. Mitigating the risk of old versions of the Java applet can be accomplished by blacklisting old, vulnerable versions using the Jar blacklist feature introduced with Java SE 6 Update 14. Vulnerability Scoring Details +---------------------------- Cisco has provided scores for the vulnerabilities in this advisory based on the Common Vulnerability Scoring System (CVSS). The CVSS scoring in this Security Advisory is done in accordance with CVSS version 2.0. CVSS is a standards-based scoring method that conveys vulnerability severity and helps determine urgency and priority of response. Cisco has provided a base and temporal score. Customers can then compute environmental scores to assist in determining the impact of the vulnerability in individual networks. Cisco has provided an FAQ to answer additional questions regarding CVSS at: http://www.cisco.com/web/about/security/intelligence/cvss-qandas.html Cisco has also provided a CVSS calculator to help compute the environmental impact for individual networks at: http://intellishield.cisco.com/security/alertmanager/cvss * CSCsy00904 & CSCsy05934 - Arbitrary Program Execution Vulnerability CVSS Base Score - 7.6 Access Vector - Network Access Complexity - High Authentication - None Confidentiality Impact - Complete Integrity Impact - Complete Availability Impact - Complete CVSS Temporal Score - 6.3 Exploitability - Functional Remediation Level - Official-Fix Report Confidence - Confirmed * CSCta40556 -- AnyConnect: Security issue with SBL on versions prior to 2.3 CVSS Base Score - 7.2 Access Vector - Local Access Complexity - Low Authentication - None Confidentiality Impact - Complete Integrity Impact - Complete Availability Impact - Complete CVSS Temporal Score - 6.0 Exploitability - Functional Remediation Level - Official-Fix Report Confidence - Confirmed Impact ====== Arbitrary Program Execution Vulnerability +---------------------------------------- Exploitation of this vulnerability may allow an attacker to execute arbitrary programs on the computer of a Cisco AnyConnect Secure Mobility Client user with the privileges of the user who is establishing the VPN connection. Software Versions and Fixes =========================== When considering software upgrades, also consult: http://www.cisco.com/go/psirt and any subsequent advisories to determine exposure and a complete upgrade solution. In all cases, customers should exercise caution to be certain the devices to be upgraded contain sufficient memory and that current hardware and software configurations will continue to be supported properly by the new release. If the information is not clear, contact the Cisco Technical Assistance Center (TAC) or your contracted maintenance provider for assistance. +------------------------------------------------------------+ | Vulnerability | Platform | First Fixed | | | | Release | |----------------------------+---------------+---------------| | | Microsoft | 2.3.185 | | Arbitrary Program | Windows | | |Execution Vulnerability |---------------+---------------| | | Linux, Apple | 2.5.3041 and | | | Mac OS X | 3.0.629 | |----------------------------+---------------+---------------| | | Microsoft | 2.3.254 | | Local Privilege Escalation | Windows | | |Vulnerability |---------------+---------------| | | Linux, Apple | Not affected | | | Mac OS X | | +------------------------------------------------------------+ Recommended Releases The following table lists all recommended releases. These recommended releases contain the fixes for all vulnerabilities in this advisory. Cisco recommends upgrading to a release that is equal to or later than these recommended releases. Workarounds =========== There are no workarounds for the vulnerabilities that are described in this advisory. Obtaining Fixed Software ======================== Cisco has released free software updates that address these vulnerabilities. Prior to deploying software, customers should consult their maintenance provider or check the software for feature set compatibility and known issues specific to their environment. Customers may only install and expect support for the feature sets they have purchased. By installing, downloading, accessing or otherwise using such software upgrades, customers agree to be bound by the terms of Cisco's software license terms found at: http://www.cisco.com/en/US/docs/general/warranty/English/EU1KEN_.html or as otherwise set forth at Cisco.com Downloads at: http://www.cisco.com/public/sw-center/sw-usingswc.shtml Do not contact psirt@cisco.com or security-alert@cisco.com for software upgrades. Customers with Service Contracts +------------------------------- Customers with contracts should obtain upgraded software through their regular update channels. For most customers, this means that upgrades should be obtained through the Software Center on Cisco's worldwide website at http://www.cisco.com. Customers using Third Party Support Organizations +------------------------------------------------ Customers whose Cisco products are provided or maintained through prior or existing agreements with third-party support organizations, such as Cisco Partners, authorized resellers, or service providers should contact that support organization for guidance and assistance with the appropriate course of action in regards to this advisory. The effectiveness of any workaround or fix is dependent on specific customer situations, such as product mix, network topology, traffic behavior, and organizational mission. Due to the variety of affected products and releases, customers should consult with their service provider or support organization to ensure any applied workaround or fix is the most appropriate for use in the intended network before it is deployed. Customers without Service Contracts +---------------------------------- Customers who purchase direct from Cisco but do not hold a Cisco service contract, and customers who purchase through third-party vendors but are unsuccessful in obtaining fixed software through their point of sale should acquire upgrades by contacting the Cisco Technical Assistance Center (TAC). TAC contacts are as follows. * +1 800 553 2447 (toll free from within North America) * +1 408 526 7209 (toll call from anywhere in the world) * e-mail: tac@cisco.com Customers should have their product serial number available and be prepared to give the URL of this notice as evidence of entitlement to a free upgrade. Free upgrades for non-contract customers must be requested through the TAC. Refer to: http://www.cisco.com/en/US/support/tsd_cisco_worldwide_contacts.html for additional TAC contact information, including localized telephone numbers, and instructions and e-mail addresses for use in various languages. Exploitation and Public Announcements ===================================== The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerability described in this advisory. The Arbitrary Program Execution Vulnerability was discovered by Elazar Broad and reported to Cisco by iDefense. Status of this Notice: FINAL ============================ THIS DOCUMENT IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE INFORMATION ON THE DOCUMENT OR MATERIALS LINKED FROM THE DOCUMENT IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS DOCUMENT AT ANY TIME. A stand-alone copy or Paraphrase of the text of this document that omits the distribution URL in the following section is an uncontrolled copy, and may lack important information or contain factual errors. Distribution ============ This advisory is posted on Cisco's worldwide website at: http://www.cisco.com/warp/public/707/cisco-sa-20110601-ac.shtml In addition to worldwide web posting, a text version of this notice is clear-signed with the Cisco PSIRT PGP key and is posted to the following e-mail and Usenet news recipients. * cust-security-announce@cisco.com * first-bulletins@lists.first.org * bugtraq@securityfocus.com * vulnwatch@vulnwatch.org * cisco@spot.colorado.edu * cisco-nsp@puck.nether.net * full-disclosure@lists.grok.org.uk * comp.dcom.sys.cisco@newsgate.cisco.com Future updates of this advisory, if any, will be placed on Cisco's worldwide website, but may or may not be actively announced on mailing lists or newsgroups. Users concerned about this problem are encouraged to check the above URL for any updates. Revision History ================ +---------------------------------------+ | Revision | | Initial | | 1.0 | 2011-June-01 | public | | | | release. | +---------------------------------------+ Cisco Security Procedures ========================= Complete information on reporting security vulnerabilities in Cisco products, obtaining assistance with security incidents, and registering to receive security information from Cisco, is available on Cisco's worldwide website at: http://www.cisco.com/en/US/products/products_security_vulnerability_policy.html This includes instructions for press inquiries regarding Cisco security notices. All Cisco security advisories are available at: http://www.cisco.com/go/psirt +-------------------------------------------------------------------- Copyright 2010-2011 Cisco Systems, Inc. All rights reserved. +-------------------------------------------------------------------- -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (Darwin) iF4EAREIAAYFAk3mbJUACgkQQXnnBKKRMNBBxAD+Oh7XQCOtCDOFCY8K1hWFAV/K iwgK2hG+GNV39PPndfQA/0Sked3glEypuwev05ULO4ukTAPoDI5CJLnb4W4TKjL8 =pAlh -----END PGP SIGNATURE----- . ---------------------------------------------------------------------- Join Secunia @ FIRST Conference, 12-17 June, Hilton Vienna, Austria See to the presentation "The Dynamics and Threats of End-Point Software Portfolios" by Secunia's Research Analyst Director, Stefan Frei. Read more: http://conference.first.org/ ---------------------------------------------------------------------- TITLE: Cisco AnyConnect VPN Client Two Vulnerabilities SECUNIA ADVISORY ID: SA44812 VERIFY ADVISORY: Secunia.com http://secunia.com/advisories/44812/ Customer Area (Credentials Required) https://ca.secunia.com/?page=viewadvisory&vuln_id=44812 RELEASE DATE: 2011-06-03 DISCUSS ADVISORY: http://secunia.com/advisories/44812/#comments AVAILABLE ON SITE AND IN CUSTOMER AREA: * Last Update * Popularity * Comments * Criticality Level * Impact * Where * Solution Status * Operating System / Software * CVE Reference(s) http://secunia.com/advisories/44812/ ONLY AVAILABLE IN CUSTOMER AREA: * Authentication Level * Report Reliability * Secunia PoC * Secunia Analysis * Systems Affected * Approve Distribution * Remediation Status * Secunia CVSS Score * CVSS https://ca.secunia.com/?page=viewadvisory&vuln_id=44812 ONLY AVAILABLE WITH SECUNIA CSI AND SECUNIA PSI: * AUTOMATED SCANNING http://secunia.com/vulnerability_scanning/personal/ http://secunia.com/vulnerability_scanning/corporate/wsus_sccm_3rd_third_party_patching/ DESCRIPTION: Two vulnerabilities have been reported in Cisco AnyConnect VPN Client, which can be exploited by malicious people with physical access to bypass certain security restrictions and by malicious people to compromise a user's system. Successful exploitation of this vulnerability requires the Start Before Logon (SBL) feature to be enabled. 2) An error in the helper application used for remote deployment of the client (e.g. SOLUTION: Update to a fixed version (please see the vendor's advisory for details). PROVIDED AND/OR DISCOVERED BY: 1) Reported to the vendor by a customer. 2) The vendor credits Elazar Broad via iDefense. ORIGINAL ADVISORY: Cisco (cisco-sa-20110601-ac): http://www.cisco.com/warp/public/707/cisco-sa-20110601-ac.shtml OTHER REFERENCES: Further details available in Customer Area: http://secunia.com/products/corporate/EVM/ DEEP LINKS: Further details available in Customer Area: http://secunia.com/products/corporate/EVM/ EXTENDED DESCRIPTION: Further details available in Customer Area: http://secunia.com/products/corporate/EVM/ EXTENDED SOLUTION: Further details available in Customer Area: http://secunia.com/products/corporate/EVM/ EXPLOIT: Further details available in Customer Area: http://secunia.com/products/corporate/EVM/ ---------------------------------------------------------------------- About: This Advisory was delivered by Secunia as a free service to help private users keeping their systems up to date against the latest vulnerabilities. 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IOT TAXONOMY

AFFECTED PRODUCTS

CVSS

PROBLEMTYPE DATA

THREAT TYPE

local

TYPE

permissions and access control

CONFIGURATIONS

PATCH

EXTERNAL IDS

REFERENCES

CREDITS

Cisco

SOURCES

LAST UPDATE DATE

2025-04-11T23:13:01.046000+00:00

SOURCES UPDATE DATE

SOURCES RELEASE DATE