ID

VAR-201110-0453

CVE

CVE-2011-3304

TITLE

Cisco Adaptive Security Appliances Device and Cisco Catalyst 6500 Service disruption in the series (DoS) Vulnerabilities

DESCRIPTION

Cisco Adaptive Security Appliances (ASA) 5500 series devices, and the ASA Services module in Cisco Catalyst 6500 series devices, with software 7.2 before 7.2(5.3), 8.0 before 8.0(5.25), 8.1 before 8.1(2.50), 8.2 before 8.2(5.11), 8.3 before 8.3(2.23), 8.4 before 8.4(2), and 8.5 before 8.5(1.1) allow remote attackers to cause a denial of service (device reload) via crafted MSN Instant Messenger traffic, aka Bug ID CSCtl67486. The problem is Bug ID CSCtl67486 It is a problem.Skillfully crafted by a third party MSN Instant Messenger Service disruption through traffic (DoS) There is a possibility of being put into a state. An attacker can exploit this issue to cause a vulnerable device to reload, triggering a denial-of-service condition. This issue is tracked by Cisco Bug ID CSCtl67486. Workarounds for some of the vulnerabilities are provided in this advisory. This advisory is posted at http://www.cisco.com/warp/public/707/cisco-sa-20111005-asa.shtml. A separate Cisco Security Advisory has been published to disclose the vulnerabilities that affect the FWSM. Affected versions of Cisco ASA Software will vary depending on the specific vulnerability. Vulnerable Products +------------------ For specific version information, refer to the Software Versions and Fixes section of this advisory. MSN IM inspection is not enabled by default. Administrators can enable MSN IM inspection and specify actions when a message violates a parameter, create an IM inspection policy map. In order to enable TACACS+ for authentication, authorization, or accounting (AAA), you must first create at least one AAA server group per AAA protocol and add one or more servers to each group with the "aaa-server" command. You identify AAA server groups by name. SunRPC inspection is enabled by default. To check if SunRPC inspection is enabled, issue the "show service-policy | include sunrpc" command and confirm that output, such as what is displayed in the following example, is returned. ciscoasa# show service-policy | include sunrpc Inspect: sunrpc, packet 0, drop 0, reset-drop 0 The following configuration commands are used to enable SunRPC inspection in the Cisco ASA. class-map inspection_default match default-inspection-traffic ! policy-map global_policy class inspection_default ... inspect sunrpc ... ILS inspection is not enabled by default. To check if ILS inspection is enabled, issue the "show service-policy | include ils" command and confirm that output, such as what is displayed in the following example, is returned. ciscoasa# show service-policy | include ils Inspect: ils, packet 0, drop 0, reset-drop 0 The following configuration commands are used to enable ILS inspection in the Cisco ASA. class-map inspection_default match default-inspection-traffic ! policy-map global_policy class inspection_default ... inspect ils ... ! service-policy global_policy global How to Determine the Running Software Version +-------------------------------------------- To determine whether a vulnerable version of Cisco ASA Software is running on an appliance, administrators can issue the "show version" command. The following example shows a Cisco ASA 5500 Series Adaptive Security Appliance that is running software version 8.4(1): ASA#show version | include Version Cisco Adaptive Security Appliance Software Version 8.4(1) Device Manager Version 6.4(1) Customers who use Cisco ASDM to manage devices can locate the software version in the table that is displayed in the login window or upper-left corner of the Cisco ASDM window. Products Confirmed Not Vulnerable +-------------------------------- With the exception of the Cisco FWSM, no other Cisco products are currently known to be affected by these vulnerabilities. Note: Only transit traffic can trigger this vulnerability; traffic that is destined to the appliance will not trigger the vulnerability. MSN IM inspection is not enabled by default. TACACS+ Authentication Bypass Vulnerability +------------------------------------------ AAA enables the ASA to determine who the user is (authentication), what the user can do (authorization), and what the user did (accounting). The Cisco ASA supports TACACS+ authentication for VPN users, firewall sessions, and administrative access to the device. An authentication bypass vulnerability exists in the TACACS+ implementation of the Cisco ASA. Successful exploitation could allow a remote attacker to bypass TACACS+ authentication of VPN users, firewall sessions, or administrative access to the device. The attacker needs to have access to the network between the ASA and the TACACS+ server in order to successfully exploit this vulnerability. SunRPC Inspection Denial of Service Vulnerabilities +-------------------------------------------------- The Sun RPC inspection engine performs application inspection for the Sun RPC protocol. Sun RPC is used by Network File System (NFS) and Network Information Service (NIS). Sun RPC services can run on any port. When a client attempts to access a Sun RPC service on a server, it must learn the port that service is running on. The client does this by querying the port mapper process, usually rpcbind, on the well-known port of 111. Note: Only transit traffic can trigger these vulnerabilities; traffic that is destined to the appliance will not trigger the vulnerabilities. These vulnerabilities can be triggered by using UDP packets, not TCP. SunRPC inspection is enabled by default. These vulnerabilities are documented in Cisco bug IDs CSCto92380, CSCtq06065, CSCtq06062, CSCto92398; and have been assigned CVE IDs CVE-2011-3299, CVE-2011-3300, CVE-2011-3301, and CVE-2010-3302, respectively. ILS Inspection Denial of Service Vulnerability +--------------------------------------------- The ILS inspection engine provides NAT support for Microsoft NetMeeting, SiteServer, and Active Directory products that use LDAP to exchange directory information with an ILS server. Note: Only transit traffic can trigger this vulnerability; traffic that is destined to the appliance will not trigger the vulnerability. ILS inspection is not enabled by default. 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 * CSCtl67486 ("MSN IM Inspection Denial of Service Vulnerability") 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 * CSCto40365 ("TACACS+ Authentication Bypass Vulnerability") CVSS Base Score - 7.9 Access Vector - Adjacent Network Access Complexity - Medium Authentication - None Confidentiality Impact - Complete Integrity Impact - Complete Availability Impact - Complete CVSS Temporal Score - 6.5 Exploitability - Functional Remediation Level - Official-Fix Report Confidence - Confirmed * CSCto92380, CSCtq06065, CSCtq06062, CSCto92398 ("SunRPC Inspection Denial of Service Vulnerabilities") 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 * CSCtq57697 ("ILS inspection crash on malformed ILS traffic") 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 all the DoS vulnerabilities could cause an affected device to reload. Repeated exploitation could result in a sustained DoS condition. Successful exploitation of the TACACS+ authentication bypass vulnerability could allow an attacker to bypass authentication of VPN, firewall and/or administrative sessions. 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 | Major | First Fixed | | | Release | Release | |--------------------------------+---------+-----------------| | | 7.0 | Not vulnerable | | |---------+-----------------| | | 7.1 | Not vulnerable | | |---------+-----------------| | | 7.2 | 7.2(5.3) | | |---------+-----------------| | | 8.0 | 8.0(5.25) | |MSN Instant Messeger (IM) |---------+-----------------| | Inspection Denial of Service | 8.1 | 8.1(2.50) | |Vulnerability (CSCtl67486) |---------+-----------------| | | 8.2 | 8.2(5.9) | | |---------+-----------------| | | 8.3 | 8.3(2.23) | | |---------+-----------------| | | 8.4 | 8.4(2) | | |---------+-----------------| | | 8.5 | 8.5(1.1) | |--------------------------------+---------+-----------------| | | 7.0 | 7.0(8.13) | | |---------+-----------------| | | | Vulnerable; | | | 7.1 | migrate to 7.2 | | | | (5.4) or later | | |---------+-----------------| | | 7.2 | 7.2(5.3) | | |---------+-----------------| | TACACS+ Authentication Bypass | 8.0 | 8.0(5.24) | |Vulnerability (CSCto40365) |---------+-----------------| | | 8.1 | 8.1(2.50) | | |---------+-----------------| | | 8.2 | 8.2(5) | | |---------+-----------------| | | 8.3 | 8.3(2.18) | | |---------+-----------------| | | 8.4 | 8.4(1.10) | | |---------+-----------------| | | 8.5 | 8.5(1.1) | |--------------------------------+---------+-----------------| | | 7.0 | 7.0(8.13) | | |---------+-----------------| | | | Vulnerable; | | | 7.1 | migrate to 7.2 | | | | (5.4) or later | | |---------+-----------------| | | 7.2 | 7.2(5.4) | | |---------+-----------------| | SunRPC Inspection Denial of | 8.0 | 8.0(5.25) | |Service Vulnerabilities |---------+-----------------| | | | Vulnerable; | | (CSCto92380, CSCtq06065, | 8.1 | migrate to 8.2 | | CSCtq06062, CSCto92398) | | or later | | |---------+-----------------| | | 8.2 | 8.2(5.9) | | |---------+-----------------| | | 8.3 | 8.3(2.23) | | |---------+-----------------| | | 8.4 | 8.4(2.6) | | |---------+-----------------| | | 8.5 | 8.5(1.1) | |--------------------------------+---------+-----------------| | | 7.0 | 7.0(8.13) | | |---------+-----------------| | | | Vulnerable; | | | 7.1 | migrate to 7.2 | | | | (5.4) or later | | |---------+-----------------| | | 7.2 | 7.2(5.4) | | |---------+-----------------| | ILS Inspection Denial of | 8.0 | 8.0(5.25) | |Service Vulnerability |---------+-----------------| | (CSCtq57697.) | 8.1 | 8.1(2.50) | | |---------+-----------------| | | 8.2 | 8.2(5.6) | | |---------+-----------------| | | 8.3 | 8.3(2.23) | | |---------+-----------------| | | 8.4 | 8.4(2.7) | | |---------+-----------------| | | 8.5 | 8.5(1.1) | +------------------------------------------------------------+ 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. +------------------------------------------------------------+ | Major Release | Recommended Release | |---------------+--------------------------------------------| | 7.0 | 7.0(8.13) | |---------------+--------------------------------------------| | 7.1 | Vulnerable; migrate to 7.2(5.4) or later | |---------------+--------------------------------------------| | 7.2 | 7.2(5.4) | |---------------+--------------------------------------------| | 8.0 | 8.0(5.25) | |---------------+--------------------------------------------| | 8.1 | Vulnerable; migrate to 8.2 or later | |---------------+--------------------------------------------| | 8.2 | 8.2(5.11) | |---------------+--------------------------------------------| | 8.3 | 8.3(2.24) | |---------------+--------------------------------------------| | 8.4 | 8.4(2.7) | |---------------+--------------------------------------------| | 8.5 | 8.5(1.1) | +------------------------------------------------------------+ Workarounds =========== This Cisco Security Advisory describes multiple distinct vulnerabilities. These vulnerabilities and their respective workarounds are independent of each other. MSN Instant Messeger (IM) Inspection DoS Vulnerability +----------------------------------------------------- Administrators can mitigate this vulnerability by disabling MSN IM inspection if it is not required. Administrators can disable MSN IM inspection by issuing the "no inspect im" command in class configuration sub-mode in the policy map configuration. TACACS+ Authentication Bypass Vulnerability +------------------------------------------ There are no workarounds available for this vulnerability other than using a different authentication protocol such as RADIUS, Active Directory, etc. SunRPC Inspection DoS Vulnerabilities +------------------------------------ Administrators can mitigate this vulnerability by disabling SunRPC inspection if it is not required. Administrators can disable SunRPC inspection by issuing the "no inspect sunrpc" command in class configuration sub-mode in the policy map configuration. Disabling SunRPC inspection may cause SunRPC traffic to stop through the security appliance. ILS Inspection DoS Vulnerability +------------------------------- Administrators can mitigate this vulnerability by disabling ILS inspection if it is not required. Administrators can disable ILS inspection by issuing the "no inspect ils" command in class configuration sub-mode in the policy map configuration. Disabling ILS inspection may cause ILS traffic to stop through the security appliance. 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 vulnerabilities described in this advisory. All the DoS vulnerabilities were discovered during internal testing. The TACACS+ authentication vulnerability was found during the troubleshooting of a customer 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-20111005-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 | 2011-October-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/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 v1.4.11 (GNU/Linux) iF4EAREIAAYFAk6LebsACgkQQXnnBKKRMNAHggD/dslMKLhVk9yV2wABkyniRCib jU3j+DyALI9yvmbBQPMA/jmI4QL/c3e5/xvIXhjO0kT6uUmpL8sjJQyJ58zXfMOK =1Nf6 -----END PGP SIGNATURE----- _______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.grok.org.uk/full-disclosure-charter.html Hosted and sponsored by Secunia - http://secunia.com/

AFFECTED PRODUCTS

CVSS

PROBLEMTYPE DATA

THREAT TYPE

remote

TYPE

resource management error

CONFIGURATIONS

PATCH

EXTERNAL IDS

REFERENCES

CREDITS

Cisco

SOURCES

LAST UPDATE DATE

2024-11-23T19:52:09.901000+00:00

SOURCES UPDATE DATE

SOURCES RELEASE DATE