Cisco BroadWorks SIP Denial of Service Vulnerability – Source:sec.cloudapps.cisco.com

High

Summary

• A vulnerability in the SIP processing subsystem of Cisco BroadWorks could allow an unauthenticated, remote attacker to halt the processing of incoming SIP requests, resulting in a denial of service (DoS) condition.

  This vulnerability is due to improper memory handling for certain SIP requests. An attacker could exploit this vulnerability by sending a high number of SIP requests to an affected system. A successful exploit could allow the attacker to exhaust the memory that was allocated to the Cisco BroadWorks Network Servers that handle SIP traffic. If no memory is available, the Network Servers can no longer process incoming requests, resulting in a DoS condition that requires manual intervention to recover.

  For more information about this vulnerability, see the Details section of this advisory.

  Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

  This advisory is available at the following link:
  https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-bw-sip-dos-mSySbrmt

Affected Products

• This vulnerability affects Cisco BroadWorks, regardless of device configuration.

  For information about which Cisco software releases are vulnerable, see the Fixed Software section of this advisory.

  Only products listed in the Vulnerable Products section of this advisory are known to be affected by this vulnerability.

Details

• To successfully exploit this vulnerability, an attacker would need to completely saturate the memory assigned to the Cisco BroadWorks Network Servers. Because administrators can allocate an arbitrary amount of memory to these servers, the time and the amount of SIP requests that are necessary to cause a DoS condition varies.

  Administrators can monitor the current status of the used memory and, if the usage becomes close to the maximum, restart the BroadWorks services on the Network Servers to avoid the DoS condition. During a restart, existing calls are not interrupted, but some services may be temporarily unavailable. For information on how to monitor memory utilization of Cisco BroadWorks Network Servers, see Section 19, Cisco BroadWorks System Monitoring, of the Cisco BroadWorks Maintenance Guide.

  Manually Free Allocated Memory on Cisco BroadWorks Network Servers

  If this vulnerability is successfully exploited and the DoS condition is reached, the BroadWorks Network Servers may become unresponsive. In this case, the allocated memory can be manually freed by using the restartbw command to restart the BroadWorks services on the Network Servers. For details, see Section 7.7, Restart Server, and Section 21.18, restartbw, of the Cisco BroadWorks Maintenance Guide.

  This action may cause the system to be unavailable for a period of time and should be used with care in non-redundant environments.

Workarounds

• There are no workarounds that address this vulnerability.

Fixed Software

• Cisco has released free software updates that address the vulnerability described in this advisory. Customers with service contracts that entitle them to regular software updates should obtain security fixes through their usual update channels.

  Customers may only install and expect support for software versions and feature sets for which they have purchased a license. By installing, downloading, accessing, or otherwise using such software upgrades, customers agree to follow the terms of the Cisco software license:
  https://www.cisco.com/c/en/us/products/end-user-license-agreement.html

  Additionally, customers may only download software for which they have a valid license, procured from Cisco directly, or through a Cisco authorized reseller or partner. In most cases this will be a maintenance upgrade to software that was previously purchased. Free security software updates do not entitle customers to a new software license, additional software feature sets, or major revision upgrades.

  The Cisco Support and Downloads page on Cisco.com provides information about licensing and downloads. This page can also display customer device support coverage for customers who use the My Devices tool.

  When considering software upgrades, customers are advised to regularly consult the advisories for Cisco products, which are available from the Cisco Security Advisories page, to determine exposure and a complete upgrade solution.

  In all cases, customers should ensure that the devices to be upgraded contain sufficient memory and confirm that current hardware and software configurations will continue to be supported properly by the new release. If the information is not clear, customers are advised to contact the Cisco Technical Assistance Center (TAC) or their contracted maintenance providers.

  Customers Without Service Contracts

  Customers who purchase directly from Cisco but do not hold a Cisco service contract and customers who make purchases through third-party vendors but are unsuccessful in obtaining fixed software through their point of sale should obtain upgrades by contacting the Cisco TAC: https://www.cisco.com/c/en/us/support/web/tsd-cisco-worldwide-contacts.html

  Customers should have the product serial number available and be prepared to provide the URL of this advisory as evidence of entitlement to a free upgrade.

  Fixed Releases

  In the following table(s), the left column lists Cisco software releases. The right column indicates whether a release is affected by the vulnerability that is described in this advisory and the first release that includes the fix for this vulnerability. Customers are advised to upgrade to an appropriate fixed software release as indicated in this section.

  Cisco BroadWorks Release	First Fixed Release
  Release Independent (RI)1	RI.2024.11

  1. Starting with Release 25 of Cisco BroadWorks, all server types are release-independent and follow the date-based release naming convention. For more information, see the BroadWorks Release Independent Support Policy.

  The Cisco Product Security Incident Response Team (PSIRT) validates only the affected and fixed release information that is documented in this advisory.

Exploitation and Public Announcements

• The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.

Source

• This vulnerability was found during the resolution of a Cisco TAC support case.

Cisco Security Vulnerability Policy

• To learn about Cisco security vulnerability disclosure policies and publications, see the Security Vulnerability Policy. This document also contains instructions for obtaining fixed software and receiving security vulnerability information from Cisco.

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Related to This Advisory

URL

• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-bw-sip-dos-mSySbrmt

Revision History

• Version	Description	Section	Status	Date
  1.0	Initial public release.	–	Final	2025-JAN-22

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