ID

VAR-200810-0197

CVE

CVE-2008-3816

TITLE

Cisco PIX/ASA In IPv6 Service disruption related to packet processing (DoS) Vulnerabilities

DESCRIPTION

Unspecified vulnerability in Cisco Adaptive Security Appliances (ASA) 5500 Series and PIX Security Appliances 7.2(4)9 and 7.2(4)10 allows remote attackers to cause a denial of service (device reload) via a crafted IPv6 packet. An attacker can exploit this issue to cause the affected devices to reload, denying service to legitimate users. This issue is documented in Cisco Bug ID CSCsu11575. NOTE: IPv6 is not configured by default on the devices listed above. Devices that do not support the TTL decrement feature are not vulnerable. The vulnerability is reported in version 7.2(4)9 and 7.2(4)10. NOTE: 7.0, 7.1, 8.0, and 8.1 releases are reportedly not affected. SOLUTION: Update to version 7.2(4)11. PROVIDED AND/OR DISCOVERED BY: Reported by the vendor. ORIGINAL ADVISORY: Cisco: http://www.cisco.com/warp/public/707/cisco-sa-20081022-asa.shtml ---------------------------------------------------------------------- About: This Advisory was delivered by Secunia as a free service to help everybody keeping their systems up to date against the latest vulnerabilities. Subscribe: http://secunia.com/advisories/secunia_security_advisories/ Definitions: (Criticality, Where etc.) http://secunia.com/advisories/about_secunia_advisories/ Please Note: Secunia recommends that you verify all advisories you receive by clicking the link. Secunia NEVER sends attached files with advisories. Secunia does not advise people to install third party patches, only use those supplied by the vendor. This security advisory outlines details of these vulnerabilities: * Windows NT Domain Authentication Bypass Vulnerability * IPv6 Denial of Service Vulnerability * Crypto Accelerator Memory Leak Vulnerability Note: These vulnerabilities are independent of each other. A device may be affected by one vulnerability and not affected by another. Cisco has released free software updates that address these vulnerabilities. Workarounds that mitigate some of these vulnerabilities are available. This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20081022-asa.shtml. Affected Products ================= Vulnerable Products +------------------ The following are the details about each vulnerability described within this advisory. Windows NT Domain Authentication Bypass Vulnerability +---------------------------------------------------- Because of a Microsoft Windows NT Domain authentication issue the Cisco ASA and Cisco PIX devices may be susceptible to a VPN authentication bypass vulnerability. Devices that are using any other type of external authentication (that is, LDAP, RADIUS, TACACS+, SDI, or local database) are not affected by this vulnerability. The following example demonstrates how Windows NT domain authentication is configured using the command line interface (CLI) on the Cisco ASA: aaa-server NTAuth protocol nt aaa-server NTAuth (inside) host 10.1.1.4 nt-auth-domain-controller primary1 Alternatively, to see if a device is configured for Windows NT Domain authentication use the "show running-config | include nt-auth-domain-controller" command. Alternatively, you can display the status of interfaces configured for IPv6 using the show ipv6 interface command in privileged EXEC mode, as shown in the following example: hostname# show ipv6 interface brief outside [up/up] unassigned inside [up/up] fe80::20d:29ff:fe1d:69f0 fec0::a:0:0:a0a:a70 dmz [up/up] unassigned In this example, the "outside" and "dmz" interfaces are not configured for IPv6. This memory leak occurs in the initialization code for the hardware crypto accelerator. Devices that are running software versions in the 8.0.x release are vulnerable. Products Confirmed Not Vulnerable +-------------------------------- The Cisco Firewall Services Module (FWSM) is not affected by any of these vulnerabilities. No other Cisco products are currently known to be affected by these vulnerabilities. Details ======= This Security Advisory describes multiple distinct vulnerabilities. These vulnerabilities are independent of each other. Windows NT Domain Authentication Bypass Vulnerability +---------------------------------------------------- Because of a Microsoft Windows NT Domain authentication issue the Cisco ASA and Cisco PIX devices may be susceptible to a VPN authentication bypass vulnerability. The Cisco ASA security appliance supports Microsoft Windows server operating systems that support NTLM version 1, collectively referred to as "NT servers". NT Domain authentication is supported only for remote access VPNs. Note: Devices that are running software versions in the 7.0, 7.1, 8.0, and 8.1 releases are not vulnerable. Additionally, you can add a global address to the interface. Note: Only packets that are destined to the device (not transiting the device) may trigger the effects of this vulnerability. This memory leak occurs in the initialization code for the hardware crypto accelerator. Note: Only packets destined to the device (not transiting the device) may trigger this vulnerability. The following Cisco ASA features use the services the crypto accelerator provides, and therefore may be affected by this vulnerability: * Clientless WebVPN, SSL VPN Client, and AnyConnect Connections * ASDM (HTTPS) Management Sessions * Cut-Through Proxy for Network Access * TLS Proxy for Encrypted Voice Inspection * IP Security (IPsec) Remote Access and Site-to-site VPNs * Secure Shell (SSH) Access This vulnerability is documented in Cisco Bug ID CSCsj25896 and has been assigned the Common Vulnerabilities and Exposures (CVE) identifier CVE-2008-3817. 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 * Windows NT Domain Authentication Bypass Vulnerability (CSCsu65735) CVSS Base Score - 4.3 Access Vector - Network Access Complexity - Medium Authentication - None Confidentiality Impact - Partial Integrity Impact - None Availability Impact - None CVSS Temporal Score - 3.7 Exploitability - High Remediation Level - Official-Fix Report Confidence - Confirmed * Cisco ASA may reload after receiving certain IPv6 packets (CSCsu11575) CVSS Base Score - 7.8 Access Vector - Network Access Complexity - Low Authentication - None Confidentiality Impact - None Integrity Impact - None Availability Impact - Complete CVSS Temporal Score - 6.4 Exploitability - Functional Remediation Level - Official-Fix Report Confidence - Confirmed * Crypto Accelerator Memory Leak (CSCsj25896) CVSS Base Score - 7.8 Access Vector - Network Access Complexity - Low Authentication - None Confidentiality Impact - None Integrity Impact - None Availability Impact - Complete CVSS Temporal Score - 6.4 Exploitability - Functional Remediation Level - Official-Fix Report Confidence - Confirmed Impact ====== Successful exploitation of the VPN Authentication Bypass Vulnerability may allow an attacker to successfully connect to the Cisco ASA via remote access IPSec or SSL-based VPN. Repeated exploitation could result in a sustained DoS condition. 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. The following list contains the first fixed software release of each vulnerability: +----------------------------------------+ | | Affected | First | | Vulnerability | Release | Fixed | | | | Version | |----------------+----------+------------| | | 7.0 | 7.0(8)3 | | |----------+------------| | Windows NT | 7.1 | 7.1(2)78 | |Domain |----------+------------| | Authentication | 7.2 | 7.2(4)16 | |Bypass |----------+------------| | Vulnerability | 8.0 | 8.0(4)6 | | |----------+------------| | | 8.1 | 8.1(1)13 | |----------------+----------+------------| | | 7.0 | Not | | | | Vulnerable | | |----------+------------| | | 7.1 | Not | | | | Vulnerable | |IPv6 Denial of |----------+------------| | Service | 7.2 | 7.2(4)11 | |Vulnerability |----------+------------| | | 8.0 | Not | | | | Vulnerable | | |----------+------------| | | 8.1 | Not | | | | Vulnerable | |----------------+----------+------------| | | 7.0 | Not | | | | Vulnerable | | |----------+------------| | | 7.1 | Not | | Crypto | | Vulnerable | |Accelerator |----------+------------| | Memory Leak | 7.2 | Not | | Vulnerability | | Vulnerable | | |----------+------------| | | 8.0 | 8.0(4) | | |----------+------------| | | 8.1 | 8.1(2) | +----------------------------------------+ The following maintenance software releases are the first software releases that contain the fixes for the vulnerabilities mentioned in this Security Advisory: Fixed PIX software can be downloaded from: http://www.cisco.com/pcgi-bin/tablebuild.pl/pix?psrtdcat20e2 Fix ASA software can be downloaded from: http://www.cisco.com/pcgi-bin/tablebuild.pl/asa?psrtdcat20e2 For the "Windows NT Domain Authentication Bypass Vulnerability", only interim fixed software is currently available. Customers wishing to upgrade to a fixed version instead of applying a workaround may download PIX and ASA interim versions from: http://www.cisco.com/pcgi-bin/tablebuild.pl/PIXPSIRT?psrtdcat20e2 Workarounds =========== This Security Advisory describes multiple distinct vulnerabilities. These vulnerabilities and their respective workarounds are independent of each other. Windows NT Domain Authentication Bypass Vulnerability +---------------------------------------------------- LDAP authentication is not affected by this vulnerability. As a workaround, you can enable a different type of external authentication for Remote Access VPN instead of Windows NT Domain authentication. Note: For more information about support for a specific AAA server type, refer to the following link: http://www.cisco.com/en/US/docs/security/asa/asa80/configuration/guide/aaa.html#wp1069492 IPv6 Denial of Service Vulnerability +----------------------------------- Customers that do not require IPv6 functionality on their devices can use the "no ipv6 address" interface sub-command to disable processing of IPv6 packets and eliminate their exposure Crypto Accelerator Memory Leak Vulnerability +------------------------------------------- There are no workarounds for this vulnerability. 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/products/prod_warranties_item09186a008088e31f.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 vulnerabilities described in this advisory. These vulnerabilities were found during internal testing and during the resolution of a technical support service request. 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-20081022-asa.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 1.0 | 2008-October-22 | 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/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 2007-2008 Cisco Systems, Inc. All rights reserved. +-------------------------------------------------------------------- Updated: Oct 22, 2008 Document ID: 108009 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iEYEARECAAYFAkj/S+kACgkQ86n/Gc8U/uAw4gCePvCNEXPlmyKTJaXsjCs6lJHp tGIAnR507Su0d3whQe31Igigg3xQjC1z =4yFl -----END PGP SIGNATURE-----

AFFECTED PRODUCTS

CVSS

PROBLEMTYPE DATA

THREAT TYPE

remote

TYPE

lack of information

CONFIGURATIONS

PATCH

EXTERNAL IDS

REFERENCES

CREDITS

Cisco Security bulletin

SOURCES

LAST UPDATE DATE

2024-11-23T21:24:55.281000+00:00

SOURCES UPDATE DATE

SOURCES RELEASE DATE