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Multiple Vulnerabilities in Cisco PGW Softswitch

Advisory ID: cisco-sa-20100512-pgw

http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20100512-pgw

Revision 1.0

For Public Release 2010 May 12 16:00  UTC (GMT)


Summary

Multiple vulnerabilities exist in the Cisco PGW 2200 Softswitch series of products. Each vulnerability described in this advisory is independent from other. The vulnerabilities are related to processing Session Initiation Protocol (SIP) or Media Gateway Control Protocol (MGCP) messages.

Successful exploitation of all but one of these vulnerabilities can crash the affected device. Exploitation of the remaining vulnerability will not crash the affected device, but it can lead to a denial-of-service (DoS) condition in which no new TCP-based connections will be accepted or created.

Cisco has released free software updates that address these vulnerabilities. There are no workarounds that mitigate these vulnerabilities.

This advisory is posted at http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20100512-pgw.

Affected Products

Vulnerable Products

The Cisco PGW 2200 Softswitch is affected by these vulnerabilities. The following table displays information about software releases that are affected by individual vulnerabilities. Each vulnerability in the table affects all software releases prior to the release that is listed in the table.

Cisco Bug ID

Affects All Software Releases Prior This Version(s)

CSCsz13590

9.8(1)S5

CSCsl39126

9.7(3)S11

CSCsk32606

9.7(3)S11

CSCsk44115

9.7(3)S11, 9.7(3)P11

CSCsk40030

9.7(3)S10

CSCsk38165

9.7(3)S10

CSCsj98521

9.7(3)S9, 9.7(3)P9

CSCsk04588

9.7(3)S9, 9.7(3)P9

CSCsk13561

9.7(3)S9, 9.7(3)P9

To determine the software version running on a Cisco product, log in to the device and issue the RTRV-NE command. This command displays information about the Cisco PGW 2200 Softswitch hardware, software, and current state.

The following example identifies a Cisco PGW 2200 Softswitch running software release 9.7(3):

mml> RTRV-NE
Media Gateway Controller  - MGC-01 2010-04-23 11:55:00.000
M  RTRV
   "Type:MGC (Switch Mode)"
   "Hardware platform:sun4u sparc SUNW,Sun-Fire-V210"
   "Vendor:"Cisco Systems, Inc.""
   "Location:MGC-01 - Media Gateway Controller"
   "Version:"9.7(3)""
   "Patch:"CSCOgs028/CSCOnn028""
   "Platform State:ACTIVE"
   ;

Products Confirmed Not Vulnerable

No other Cisco products are currently known to be affected by these vulnerabilities. In particular, Cisco IOS Software is not affected by these vulnerabilities.

Details

SIP is a popular signaling protocol used to manage voice and video calls across IP networks such as the Internet. SIP is responsible for handling all aspects of call setup and termination. Voice and video are the most popular types of sessions that SIP handles, but the protocol is flexible to accommodate for other applications that require call setup and termination. SIP call signaling can use UDP (port 5060), TCP (port 5060), or Transport Layer Security (TLS; TCP port 5061) as the underlying transport protocol.

MGCP is the protocol for controlling telephony gateways from external call control elements known as media gateway controllers or call agents. A telephony gateway is a network element that provides conversion between the audio signals carried on telephone circuits and data packets carried over the Internet or other packet networks.

Multiple DoS vulnerabilities exist in the Cisco PGW 2200 Softswitch SIP implementation, and one vulnerability is in the MGCP implementation.

The following vulnerabilities can cause affected devices to crash:

  • CSCsl39126 (registered customers only), CVE ID CVE-2010-0601
  • CSCsk32606 (registered customers only), CVE ID CVE-2010-0602
  • CSCsk40030 (registered customers only), CVE ID CVE-2010-0603
  • CSCsk38165 (registered customers only), CVE ID CVE-2010-0604
  • CSCsk44115 (registered customers only), CVE ID CVE-2010-1561
  • CSCsj98521 (registered customers only), CVE ID CVE-2010-1562
  • CSCsk04588 (registered customers only), CVE ID CVE-2010-1563
  • CSCsz13590 (registered customers only), CVE ID CVE-2010-1567

The following vulnerability may cause an affected device to be unable to accept or create a new TCP connection. Existing calls will not be terminated, but no new SIP connections will be established. If exploited, this vulnerability will also prevent the device from establishing any new HTTP, SSH or Telnet sessions.

  • CSCsk13561 (registered customers only), CVE ID CVE-2010-1565

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.

CSCsl39126 - Malformed MGCP packet can crash device

Calculate the environmental score of CSCsl39126

CVSS Base Score - 7.8

Access Vector

Access Complexity

Authentication

Confidentiality Impact

Integrity Impact

Availability Impact

Network

Low

None

None

None

Complete

CVSS Temporal Score - 6.4

Exploitability

Remediation Level

Report Confidence

Functional

Official-Fix

Confirmed

CSCsk32606 - Malformed SIP packet can crash device

CSCsk40030 - Malformed Session Attribute can crash device

CSCsk38165 - Device crash during SIP testing

CSCsk44115 - Device crash while processing overly long message

CSCsj98521 - Device crash while processing malformed Contact Header

CSCsk04588 - Device crash while processing malformed header

CSCsz13590 - Malformed SIP header can crash device

Calculate the environmental score of CSCsk32606, CSCsk40030, CSCsk38165, CSCsk44115, CSCsj98521, CSCsk04588, CSCsz13590

CVSS Base Score - 7.8

Access Vector

Access Complexity

Authentication

Confidentiality Impact

Integrity Impact

Availability Impact

Network

Low

None

None

None

Complete

CVSS Temporal Score - 6.4

Exploitability

Remediation Level

Report Confidence

Functional

Official-Fix

Confirmed

CSCsk13561 - Exhaustion of TCP sockets prevents device from accepting new connections

Calculate the environmental score of CSCsk13561

CVSS Base Score - 7.8

Access Vector

Access Complexity

Authentication

Confidentiality Impact

Integrity Impact

Availability Impact

Network

Low

None

None

None

Complete

CVSS Temporal Score - 6.4

Exploitability

Remediation Level

Report Confidence

Functional

Official-Fix

Confirmed

Impact

Successful exploitation of all but one vulnerability in this advisory can crash the affected device. The remaining vulnerability will not crash the affected device, but it can lead to a DoS condition in which no new TCP-based connections will be accepted or created.

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.

All vulnerabilities listed in this Security Advisory are addressed in Cisco PGW 2200 Softswitch version 9.7(3)S11, version 9.8(1)S5, and subsequent, software releases.

Workarounds

There are no workarounds for the vulnerabilities in this advisory.

In the case of the vulnerability that corresponds to Cisco Bug ID CSCsk13561, administrator must manually reboot the affected device to restore the device's ability to accept new connections. Because vulnerability prevents new TCP-based session to be created, this reboot can be initiated only from the console. If a failover device is configured, existing sessions will continue while the affected device is reloading. Without a failover device, all active sessions will be terminated while the affected device is reloading.

Additional mitigation techniques that can be deployed on Cisco devices within the network are available in the Cisco Applied Mitigation Bulletin companion document for this advisory: http://tools.cisco.com/security/center/content/CiscoAppliedMitigationBulletin/cisco-amb-20100512-pgw

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.

These vulnerabilities were discovered during internal testing.

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://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20100512-pgw

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

2010-May-12

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/web/about/security/psirt/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.