Summary: A vulnerability in the Resource Reservation Protocol (RSVP) feature of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload unexpectedly, resulting in a denial of service (DoS) condition. This vulnerability is due to a buffer overflow when processing crafted RSVP packets. An attacker could exploit this vulnerability by sending RSVP traffic to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is part of the September 2024 release of the Cisco IOS and IOS XE Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see Cisco Event Response: September 2024 Semiannual Cisco IOS and IOS XE Software Security Advisory Bundled Publication ["https://sec.cloudapps.cisco.com/security/center/viewErp.x?alertId=ERP-75169"].

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Vulnerable Products: This vulnerability affects Cisco IOS and IOS XE Software if the RSVP feature is enabled. For information about which Cisco software releases are vulnerable, see the Fixed Software ["#fs"] section of this advisory. Determine the Device Configuration To determine whether a device has RSVP enabled, use the show running-configuration | include rsvp bandwidth CLI command. If there is output, RSVP is enabled, as shown in the following example: Router# show running-config | include rsvp bandwidth ip rsvp bandwidth value

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Products Confirmed Not Vulnerable: Only products listed in the Vulnerable Products ["#vp"] section of this advisory are known to be affected by this vulnerability. Cisco has confirmed that this vulnerability does not affect the following Cisco products: IOS XR Software Meraki products NX-OS Software

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Workarounds: There are no workarounds that address this vulnerability.

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Fixed Software: Cisco has released free software updates ["https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html#ssu"] 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 ["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 ["https://www.cisco.com/c/en/us/support/index.html"] 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 ["https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html#fixes"], customers are advised to regularly consult the advisories for Cisco products, which are available from the Cisco Security Advisories page ["https://www.cisco.com/go/psirt"], 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 ["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. Cisco IOS and IOS XE Software To help customers determine their exposure to vulnerabilities in Cisco IOS and IOS XE Software, Cisco provides the Cisco Software Checker ["https://sec.cloudapps.cisco.com/security/center/softwarechecker.x"]. This tool identifies any Cisco security advisories that impact a specific software release and the earliest release that fixes the vulnerabilities that are described in each advisory (“First Fixed”). If applicable, the tool also returns the earliest release that fixes all the vulnerabilities that are described in all the advisories that the Software Checker identifies (“Combined First Fixed”). To use the tool, go to the Cisco Software Checker ["https://sec.cloudapps.cisco.com/security/center/softwarechecker.x"] page and follow the instructions. Alternatively, use the following form to determine whether a release is affected by any Cisco Security Advisory. To use the form, follow these steps: Choose which advisories the tool will search—only this advisory, only advisories with a Critical or High Security Impact Rating (SIR) ["https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html#asr"], or all advisories. Enter a release number—for example, 15.9(3)M2 or 17.3.3. Click Check. Only this advisory All Critical and High advisories All advisories

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Vulnerability Policy: To learn about Cisco security vulnerability disclosure policies and publications, see the Security Vulnerability Policy ["http://www.cisco.com/web/about/security/psirt/security_vulnerability_policy.html"]. This document also contains instructions for obtaining fixed software and receiving security vulnerability information from Cisco.

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Exploitation and Public Announcements: The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.

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Source: This vulnerability was found during internal security testing.

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