-----BEGIN PGP SIGNED MESSAGE----- Cisco Security Advisory: Vulnerability in the zlib Compression Library Revision 1.0 For Public Release 2002 April 03 16:00 (UTC +0000) - --------------------------------------------------------------------------- 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 ======= There is a vulnerability in the zlib compression library. This code is used in multiple applications. While we have not identified any Cisco product that is directly impacted by the vulnerability, there are several products that are using third-party modules that are vulnerable or that are running on an operating system that is vulnerable. This vulnerability has been publicly disclosed. Cisco PSIRT is still evaluating which products are affected by this vulnerability. There is no workaround for this vulnerability. This advisory is available at http://www.cisco.com/warp/public/707/zlib-double-free.shtml. Affected Products ================= The following products are affected: Cache Software/ACNS + Content Engine 507, 560, 590, and 7320 running Cache Software 3.1.1 or Application and Content Networking Software 4.0.x or 4.1.1 + Content Router 4430 and Content Distribution Manager 4630 and 4650 running Application and Content Networking Software 4.0.x or 4.1.1 ME1100 This product reached the end-of-life state in 2001. This product is no longer supported, and customers are strongly advised to migrate to a recent product. Cisco Intrusion Detection System Cisco IDS sensor appliances (part numbers IDS-4210, IDS-4220-E and IDS-4230-xx) are vulnerable if the sensor version as reported by nrvers is in the range 3.0(1) through 3.0(5) inclusive. The C6000 IDSM (part number WS-X6381-IDS) is not vulnerable. Metro 1500 DWDM All releases prior the software release 3.3b. Hosting Solution Engine (HSE) HSE releases 1.0 and 1.3 are vulnerable. We are still evaluating the rest of Cisco products against this vulnerability. We have verified that the following products are not vulnerable or that exposure is negligible. Note that this is not an exhaustive list. * Cisco IOS� * Cisco CatOS * Cisco SN 5420 Storage Routers * PIX Firewall * VPN 3000, 3500 * User Registration Tool (URT) Some products, such as Cisco IOS, use compressed images. In order to utilize this attack vector, an attacker would have to prepare a tampered distribution image and try to load it onto a device. That implies either physical or administrative access to the device. By having such access, an attacker is in a position to execute many other attacks, some of which are much easier to accomplish. Although Cisco will incorporate the fixed version of zlib in the subsequent software releases for products that belong to this category, that fact will not be reflected in this advisory. Details ======= There is a bug in the decompression algorithm used by the popular zlib compression library. By sending a crafted block of invalid compressed data, an attacker can cause the application to corrupt internal data. This happens when the application tries to uncompress the data. In most cases this vulnerability will cause denial of service. However, depending on the right circumstances and applications, there is a potential that an attacker could execute an arbitrary code. This code would then be executed using the privileges of the application in question. Impact ====== By repeatedly exploiting this vulnerability, an attacker can cause denial of service. It is possible that an attacker may be able to execute an arbitrary code on the target machine. In that case, this may lead to a partial or total compromise of the machine in question. Software Versions and Fixes =========================== Cache Software/ACNS ACNS 4.1.3 is the fixed release. It will be available in the second half of April 2002. ME1100 This product has reached the end-of-life state and the fix is not scheduled. Customers are strongly advised to migrate to a recent product. Cisco Intrusion Detection System Sensor appliance software version 3.1(1) is the first fixed release. It will be available on April 16, 2002. Metro 1500 DWDM The software release 3.3b is the first fixed release. It will be available on April 5, 2002. Hosting Solution Engine HSE release 1.4 contains the fix. It will be available on April 15, 2002. Obtaining Fixed Software ======================== Cisco is offering free software upgrades to address this vulnerability 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 any software release containing the feature sets they have purchased. For most customers with service contracts, this means that upgrades should be obtained through the Software Center on Cisco's Worldwide Web site 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 assistance with the upgrade. 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). In these cases, customers may only upgrade to a later version of the same release or as indicated by the applicable entry in the Software Versions and Fixes section. * +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 notice 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 =========== There is no workaround for this vulnerability. Exploitation and Public Announcements ===================================== This vulnerability was publicly announced by third parties on March 21, 2002. The related advisories can be found at: * http://www.cert.org/advisories/CA-2002-07.html * http://www.gzip.org/zlib/advisory-2002-03-11.txt Status of This Notice: INTERIM ============================== This is an interim security advisory. Cisco anticipates issuing updated versions of this notice at irregular intervals as there are material changes in the facts, and will continue to update this notice as necessary. The reader is warned that this notice may contain inaccurate or incomplete information. Although Cisco cannot guarantee the accuracy of all statements in this notice, all of the facts have been checked to the best of our ability. Cisco anticipates issuing monthly updates of this notice until it reaches FINAL status. A standalone 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 Web site at http:// www.cisco.com/warp/public/707/zlib-double-free.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-April-03 16:00 UTC+0000|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 Web site at http://www.cisco.com/warp/public/707/sec_incident_response.shtml This includes instructions for press inquiries regarding Cisco security notices. All Cisco Security Advisories are available at http://www.cisco.com/go/psirt. - --------------------------------------------------------------------------- This notice is Copyright 2002 by Cisco Systems, Inc. This notice may be redistributed freely after the release date given at the top of the text, provided that redistributed copies are complete and unmodified, and include all date and version information. - --------------------------------------------------------------------------- -----BEGIN PGP SIGNATURE----- Version: PGP 6.5.3 iQEVAwUBPKqlpw/VLJ+budTTAQFXegf/UWWmfKJ9LdAaoaTivOIcDCKN0/YSxIbC wEp9bZOwsQcXJXcpheY3S5w0asg13jnyPsTmlxGG7N9iE/23Fk+ls4VqIC6jHIs0 qlnBN009cy32p8nnoyh5sHQFaKcV+eamyF0IzyaSAsrKX9kWTdXcJiKoQQ5qrXma RdxPuwRyNZY0ypaD9ahlocp/GVBfzSIJgBIXyW8wAZiGXoMjWt9x6wyFE930WtjB NQMg5i5Ie4qny1okItiLc86qnN32hki+lsKMGNF9YXfHGayWDbJVWWBncsB4OG2e TvPzFgklwhvQ7vWt+aRuInxhv+kBDe0Zt6gPLy5Qkw6PDqH++UDtnQ== =OCLo -----END PGP SIGNATURE-----