Summary
Affected Products
Details
Impact
Software Versions and Fixes
Workarounds
Obtaining Fixed Software
Exploitation and Public Announcements
Status of This Advisory: FINAL
Distribution
Revision History
Cisco Security Procedures
The Cisco PIX Firewall provides robust, enterprise-class security services including stateful inspection firewalling, standards-based IP Security (IPsec) Virtual Private Networking (VPN), intrusion protection and much more in cost-effective, easy to deploy solutions.
Two vulnerabilities have been resolved for the PIX firewall for which fixes are available. These vulnerabilities are documented as Cisco bug ID CSCdv83490 and CSCdx35823. 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/cisco-sa-20021120-pix-vulnerability.shtml.
This section provides details on affected products.
All PIX Firewall units running the vulnerable releases and using the specific features are affected by these vulnerabilities.
|
DDTs—Description |
Affected Release |
|---|---|
|
CSCdv83490—While processing initial contact notify messages the PIX does not delete duplicate Internet Security Authentication Key Management Protocol Security Associations (ISAKMP SAs) with the peer. |
6.0.3 and earlier 6.1.3 and earlier |
|
CSCdx35823—Buffer overflow while doing HTTP traffic authentication using Terminal Access Controller Access Control System Plus (TACACS+) or Remote Authentication Dial-In User Service (RADIUS). |
5.2.8 and earlier 6.0.3 and earlier 6.1.3 and earlier 6.2.1 and earlier |
To determine your software revision, type show version at the command line prompt.
No other Cisco products are currently known to be affected by these vulnerabilities.
CSCdv83490
When a user establishes a VPN session upon successful peer and user authentication, the PIX creates an ISAKMP SA associating the user and his IP address.
If an attacker is now able to block the logged-in user's connection and establish a connection to the PIX using the same IP address as that of the user, he will be able to establish a VPN session with the PIX, using only peer authentication, provided he already has access to the peer authentication key also known as the group pre-shared key (PSK) or group password key.
CSCdx35823
A user starting a connection via FTP, Telnet, or over the World Wide Web (HTTP) is prompted for their user name and password. If the user name and password are verified by the designated TACACS+ or RADIUS authentication server, the PIX Firewall unit will allow further traffic between the authentication server and the connection to interact independently through the PIX Firewall unit's "cut-through proxy" feature.
The PIX may crash and reload due to a buffer overflow vulnerability while processing HTTP traffic requests for authentication using TACACS+ or RADIUS.
The Internetworking Terms and Acronyms online guide can be found at http://www.cisco.com/univercd/cc/td/doc/cisintwk/ita/index.htm. The Cisco Systems Terms and Acronyms online guide can be found at http://www.cisco.com/univercd/cc/td/doc/cisintwk/ita/cisco12.htm.
These vulnerabilities are documented in the Bug Toolkit as Bug IDs CSCdv83490 and CSCdx35823, and can be viewed after 2002 November 21 at 1600 UTC. To access this tool, you must be a registered user and you must be logged in.
This section describes the impact of this vulnerability.
|
DDTs—Description |
Impact |
|---|---|
|
CSCdv83490—While processing initial contact notify messages the PIX does not delete duplicate ISAKMP SA's with the peer. |
This vulnerability can be exploited to initiate a Man-In-The-Middle attack for VPN sessions to the PIX. |
|
CSCdx35823 - Buffer overflow while doing HTTP traffic authentication using TACACS+ or RADIUS. |
This vulnerability can be exploited to initiate a Denial-of-Service attack. |
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.
|
DDTs—Description |
Fixed Releases |
|---|---|
|
CSCdv83490—While processing initial contact notify messages the PIX does not delete duplicate ISAKMP SAs with the peer. |
6.0.4 and later 6.1.4 and later 6.2.1 and later |
|
CSCdx35823—Buffer overflow while doing HTTP traffic authentication using TACACS+ or RADIUS. |
5.2.9 and later 6.0.4 and later 6.1.4 and later 6.2.2 and later |
The procedure to upgrade to the fixed software version is detailed at http://www.cisco.com/univercd/cc/td/doc/product/iaabu/pix/pix_sw/index.htm.
There are no workarounds for these vulnerabilities. The Cisco PSIRT recommends that affected users upgrade to a fixed software version of code.
Cisco has made free software available to address this vulnerability for affected customers. 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/public/sw-license-agreement.html, or as otherwise set forth at Cisco.com Downloads at http://www.cisco.com/public/sw-center/sw-usingswc.shtml.
Do not contact either "psirt@cisco.com" or "security-alert@cisco.com" for software upgrades.
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 whose Cisco products are provided or maintained through prior or existing agreement 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 who purchase direct 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 get their upgrades by contacting the Cisco Technical Assistance Center (TAC). TAC contacts are as follows.
Have your product serial number available and give the URL of this notice as evidence of your entitlement to a free upgrade. Free upgrades for non-contract customers must be requested through the TAC.
Refer to 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.
The Cisco PSIRT is not aware of any malicious use of the vulnerabilities described in this advisory.
These vulnerabilities were reported to PSIRT by Cisco engineering and customers.
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.
This advisory will be posted on Cisco's worldwide website at http://www.cisco.com/warp/public/707/cisco-sa-20021120-pix-vulnerability.shtml.
In addition to worldwide website posting, a text version of this advisory is clear-signed with the Cisco PSIRT PGP key having the fingerprint FEB1 1B89 A64B 60BB 4770 D1CE 93D2 FF06 F236 759C and is posted to the following e-mail and Usenet news recipients:
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 1.0 |
2002-Nov-20 |
Initial public release |
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 advisories. All Cisco security advisories are available at http://www.cisco.com/go/psirt.
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| Updated: Nov 20, 2002 | Document ID: 28947 |