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-----BEGIN PGP SIGNED MESSAGE----- =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2002.491 -- Cisco Security Advisory Cisco VPN Client Multiple Vulnerabilities - Second Set 06 September 2002 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: VPN client software prior to v3.6 Vendor: Cisco Systems Operating System: Windows Red Hat Linux Solaris Mac OS X Impact: Denial of Service Access Privileged Data Access Required: Remote Ref: ESB-2002.417 - --------------------------BEGIN INCLUDED TEXT-------------------- - -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Cisco Security Advisory: Cisco VPN Client Multiple Vulnerabilities - Second Set Revision 1.0 For Public Release 2002 September 05 UTC 1500 ---------------------------------------------------------------------- Contents Summary Affected Products Details Impact Software Versions and Fixes Obtaining Fixed Software Workarounds Exploitation and Public Announcements Status of This Notice Distribution Revision History Cisco Security Procedures ---------------------------------------------------------------------- Summary Multiple vulnerabilities exist in the Cisco Virtual Private Network (VPN) Client software. These vulnerabilities are documented as Cisco Bug IDs CSCdt35749, CSCdt60391, CSCdw87717, CSCdx89416 and CSCdy37058. There are no workarounds available to mitigate the effects of these vulnerabilities. This advisory will be posted at http://www.cisco.com/warp/public/707/vpnclient-multiple2-vuln-pub.shtml. Affected Products The VPN Client software program runs on the following platforms. * Microsoft Windows based PC. * Red Hat Version 6.2 Linux (Intel), or compatible distribution, using kernel Version 2.2.12 or later. It does not support kernel Version 2.5. * Solaris UltraSPARC running a 32-bit or a 64-bit kernel OS Version 2.6 or later. * Mac OS X Version 10.1.0 or later. +-------------------------------------------------+ | DDTS Description | Affected Releases | |-----------------------------+-------------------| | CSCdt35749 - NETBIOS TCP | * earlier than | | packet vulnerability | 3.0.5 | | | * 2.x.x | |-----------------------------+-------------------| | CSCdt60391 - Group | * earlier than | | passwords visible using | 3.5.1C | | utility program | * 3.1.x | | | * 3.0.x | | | * 2.x.x | |-----------------------------+-------------------| | CSCdw87717 - Concentrator | * earlier than | | certificate identity | 3.5.1C | | vulnerability | * 3.1.x | | | * 3.0.x | | | * 2.x.x | |-----------------------------+-------------------| | CSCdx89416 - Random number | * earlier than | | generation improvement | 3.5.2B | | | * 3.1.x | | | * 3.0.x | | | * 2.x.x | |-----------------------------+-------------------| | CSCdy37058 - TCP filter | * 3.6(Rel) | | vulnerability | * earlier than | | | 3.5.4 | | | * 3.1.x | | | * 3.0.x | | | * 2.x.x | +-------------------------------------------------+ No other Cisco products are currently known to be affected by these vulnerabilities. Details The VPN Client software program on a remote workstation, communicating with a Cisco VPN device on an enterprise network or with a service provider, creates a secure connection over the Internet. Through this connection you can access a private network as if you were an onsite user. +-------------------------------------------------+ | DDTS Description | Details | |--------------------+----------------------------| | CSCdt35749 - | The VPN Client is | | NETBIOS TCP packet | vulnerable to NETBIOS TCP | | vulnerability | packets that have their | | | source and destination | | | ports set to 137 (NETBIOS | | | Name Service). Upon | | | receiving such a packet, | | | the VPN Client crashes. | |--------------------+----------------------------| | CSCdt60391 - Group | There is a utility program | | passwords visible | under Windows that can | | using utility | decipher the group | | program | password field, which is | | | shown as a series of | | | asterisks (***...) on the | | | authentication property | | | page of the VPN Client. | |--------------------+----------------------------| | CSCdw87717 - | When a VPN Client connects | | Concentrator | to a VPN Concentrator | | certificate | using certificates, the | | identity | VPN Client does not have | | vulnerability | the ability to verify that | | | specific certificate DN | | | fields match in the | | | certificate received from | | | the VPN Concentrator. | |--------------------+----------------------------| | CSCdx89416 - | The random number | | Random number | generation process in the | | generation | VPN Client software has | | improvement | been significantly | | | improved to increase the | | | randomness of the | | | generated numbers. | |--------------------+----------------------------| | CSCdy37058 - TCP | It is possible to get the | | filter | VPN Client, which is | | vulnerability | configured for all tunnel | | | mode (split tunneling | | | disabled mode), to | | | acknowledge a TCP packet | | | via the tunnel-assigned | | | IP, when the packet is | | | sent to it from outside | | | the tunnel. The 3.5.x | | | releases are protected | | | against this vulnerability | | | if the firewall is | | | configured to be in | | | "always on" mode. The | | | 3.6(Rel) release is | | | vulnerable even when the | | | firewall is in "always on" | | | mode. | +-------------------------------------------------+ These vulnerabilities are documented in the Cisco Bug Toolkit as Bug IDs CSCdt35749, CSCdt60391, CSCdw87717, CSCdx89416 and CSCdy37058, and can be viewed after 2002 September 6 at 1500 UTC. To access this tool, you must be a registered user and you must be logged in. Impact +-------------------------------------------------+ | DDTS Description | Impact | |---------------------+---------------------------| | CSCdt35749 - | This vulnerability can be | | NETBIOS TCP packet | exploited to initiate a | | vulnerability | denial-of-service attack. | |---------------------+---------------------------| | CSCdt60391 - Group | Unintended disclosure of | | passwords visible | the group password. | | using utility | | | program | | |---------------------+---------------------------| | CSCdw87717 - | This vulnerability could | | Concentrator | be exploited to initiate | | certificate | a man-in-the-middle | | identity | attack. | | vulnerability | | |---------------------+---------------------------| | CSCdx89416 - Random | Improvement in the | | number generation | randomness of random | | improvement | numbers generated for use | | | by the VPN Client. | |---------------------+---------------------------| | CSCdy37058 - TCP | This vulnerability could | | filter | be exploited to leak | | vulnerability | information about the VPN | | | Client workstation. | +-------------------------------------------------+ Software Versions and Fixes +-------------------------------------------------+ | DDTS Description | Fixed Releases | |---------------------------+---------------------| | CSCdt35749 - NETBIOS TCP | * 3.6(Rel) or | | packet vulnerability | later | | | * 3.5(Rel) or | | | later | | | * 3.1(Rel) or | | | later | | | * 3.0.5 or later | |---------------------------+---------------------| | CSCdt60391 - Group | * 3.6(Rel) or | | passwords visible using | later | | utility program | * 3.5.1C or later | |---------------------------+---------------------| | CSCdw87717 - Concentrator | * 3.6(Rel) or | | certificate identity | later | | vulnerability | * 3.5.1C or later | |---------------------------+---------------------| | CSCdx89416 - Random | * 3.6(Rel) or | | number generation | later | | improvement | * 3.5.2B or later | |---------------------------+---------------------| | CSCdy37058 - TCP filter | * 3.6.1 or later | | vulnerability | * 3.5.4 or later | +-------------------------------------------------+ The procedure to upgrade on the various platforms to the fixed software version is detailed in the documentation available at http://www.cisco.com/univercd/cc/td/doc/product/vpn/client/. Obtaining Fixed Software Cisco is offering free software upgrades to address these vulnerabilities for all affected customers. Customers may only install and expect support for the feature sets they have purchased. Customers with service contracts should contact their regular update channels to obtain the free software upgrade identified via this advisory. For most customers with service contracts, this means that upgrades should be obtained through the Software Center on Cisco's worldwide website at http://www.cisco.com/kobayashi/sw-center/vpn/client/ . To access the software download URL, you must be a registered user and you must be logged in. Customers whose Cisco products are provided or maintained through a prior or existing agreement with third-party support organizations such as Cisco Partners, authorized resellers, or service providers should contact that support organization for assistance with obtaining the free software upgrade(s). Customers who purchased directly from Cisco but who do not hold a Cisco service contract, and customers who purchase through third-party vendors but are unsuccessful at obtaining fixed software through their point of sale, should obtain fixed software by contacting the Cisco Technical Assistance Center (TAC) using the contact information listed below. In these cases, customers are entitled to obtain an upgrade to a later version of the same release or as indicated by the applicable corrected software version in Software Versions and Fixes. Cisco 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 See http://www.cisco.com/warp/public/687/Directory/DirTAC.shtml for additional TAC contact information, including special localized telephone numbers and instructions and e-mail addresses for use in various languages. Please have your product serial number available and give the URL of this advisory as evidence of your entitlement to a free upgrade. Please do not contact either "psirt@cisco.com" or "security-alert@cisco.com" for software upgrades. Workarounds +-------------------------------------------------+ | DDTS Description | Workaround | |-------------------------------+-----------------| | CSCdt35749 - NETBIOS TCP | There is no | | packet vulnerability | workaround. | |-------------------------------+-----------------| | CSCdt60391 - Group passwords | There is no | | visible using utility program | workaround. | |-------------------------------+-----------------| | CSCdw87717 - Concentrator | There is no | | certificate identity | workaround. | | vulnerability | | |-------------------------------+-----------------| | CSCdx89416 - Random number | Not applicable. | | generation improvement | | |-------------------------------+-----------------| | CSCdy37058 - TCP filter | There is no | | vulnerability | workaround. | +-------------------------------------------------+ The Cisco PSIRT recommends that affected users upgrade to a fixed software version of code. Exploitation and Public Announcements The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerabilities described in this advisory. These vulnerabilities were reported to PSIRT by internal development testing and customers. Status of This Notice: FINAL This is a final notice. Although Cisco cannot guarantee the accuracy of all statements in this advisory, all of the facts have been checked to the best of our ability. Cisco does not anticipate issuing updated versions of this advisory unless there is some material change in the facts. Should there be a significant change in the facts, Cisco may update this advisory. A stand-alone copy or paraphrase of the text of this security advisory that omits the distribution URL in the following section is an uncontrolled copy, and may lack important information or contain factual errors. Distribution This notice will be posted on Cisco's worldwide website at http://www.cisco.com/warp/public/707/vpnclient-multiple2-vuln-pub.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 * bugtraq@securityfocus.com * first-teams@first.org (includes CERT/CC) * cisco@spot.colorado.edu * comp.dcom.sys.cisco * firewalls@lists.gnac.com * Various internal Cisco mailing lists Future updates of this notice, if any, will be placed on Cisco's worldwide web server, but may or may not be actively announced on mailing lists or newsgroups. Users concerned about this problem are encouraged to check the URL given above for any updates. Revision History +------------------------------------------------------------+ | Revision 1.0 | 2002-September-05 | Initial 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/go/psirt. This includes instructions for press inquiries regarding Cisco security advisories. ---------------------------------------------------------------------- This notice is Copyright 2002 by Cisco Systems, Inc. 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