{ "document": { "acknowledgments": [ { "summary": "This vulnerability was found during the resolution of a Cisco TAC support case." } ], "category": "csaf_security_advisory", "csaf_version": "2.0", "notes": [ { "category": "summary", "title": "Summary", "text": "A vulnerability in the RADIUS message processing feature of Cisco Identity Services Engine (ISE) could allow an unauthenticated, remote attacker to cause the affected system to stop processing RADIUS packets.\r\n\r\nThis vulnerability is due to improper handling of certain RADIUS accounting requests. An attacker could exploit this vulnerability by sending a crafted authentication request to a network access device (NAD) that uses Cisco ISE for authentication, authorization, and accounting (AAA). This would eventually result in the NAD sending a RADIUS accounting request packet to Cisco ISE. An attacker could also exploit this vulnerability by sending a crafted RADIUS accounting request packet to Cisco ISE directly if the RADIUS shared secret is known. A successful exploit could allow the attacker to cause the RADIUS process to unexpectedly restart, resulting in authentication or authorization timeouts and denying legitimate users access to the network or service. Clients already authenticated to the network would not be affected.\r\n\r\nNote: To recover the ability to process RADIUS packets, a manual restart of the affected Policy Service Node (PSN) may be required. For more information, see the Details [\"#details\"] section of this advisory.\r\n\r\nCisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.\r\n\r\n" }, { "category": "general", "title": "Vulnerable Products", "text": "This vulnerability affects Cisco ISE PSNs that are configured with RADIUS. If Cisco ISE is being used for TACACS only, the device is not affected.\r\n\r\nNote: RADIUS is enabled by default and cannot be disabled. The default RADIUS policies may need to be configured to deny access to all users and devices if Cisco ISE is being used for TACACS only.\r\n\r\nNote: For the exploit to be successful, attackers must have one of the following:\r\n\r\nValid user credentials\r\nA NAD shared secret that can be used to connect to Cisco ISE\r\nAccess to a NAD that connects to a Cisco ISE deployment and that is configured with MAC Authentication Bypass (MAB) so that the authentication policy succeeds even if a user is not found\r\n\r\nDetermine PSN Configuration\r\n\r\nTo determine whether a node in the Cisco ISE deployment is a PSN, use the following steps:\r\n\r\nLog in to the Cisco ISE web-based management interface.\r\nClick the menu icon.\r\nChoose Administration > System > Deployment.\r\nLook at the Personas column in the table for the nodes in the deployment. If a node has Policy Service listed, the node is affected by this vulnerability. If Policy Service is not listed, the node is not affected by this vulnerability.\r\n\r\nDetermine the RADIUS Policy\r\n\r\nIf a deployment is being used for TACACS only and the RADIUS policy is set to DenyAccess, the deployment is not affected by this vulnerability.\r\n\r\nTo determine whether a deployment has a DenyAccess RADIUS policy in effect, use the following steps:\r\n\r\nLog in to the Cisco ISE web-based management interface.\r\nClick the menu icon.\r\nChoose Policy > Policy Sets. If RADIUS has never been deployed, only the Default policy should be listed. If more than one policy is listed, this deployment might be serving as a RADIUS server.\r\nClick the arrow to check the Default policy.\r\nIn the Authentication Policy section, verify the following:\r\nAll rules are disabled except the Default rule.\r\nUnder Default > Options, all options are REJECT or DROP.\r\n\r\nIn the Authorization Policy - Local Exceptions section, verify that all rules are disabled.\r\nIn the Authorization Policy - Global Exceptions section, verify that all rules are disabled.\r\nIn the Authorization Policy section, verify the following:\r\nAll rules are disabled except the Default rule.\r\nThe Default rule's profile is DenyAccess." }, { "category": "general", "title": "Products Confirmed Not Vulnerable", "text": "Only products listed in the Vulnerable Products [\"#vp\"] section of this advisory are known to be affected by this vulnerability." }, { "category": "general", "title": "Details", "text": "The affected Cisco ISE PSN should restart automatically. If the restart fails, a manual restart should be performed. The recommendations for a manual restart are as follows:\r\n\r\nIn a one-node deployment, the PSN persona will be located on the single node. That node will need to be restarted.\r\nIn a multi-node deployment, only the affected PSN node will need to be restarted.\r\n\r\nFor more information on Cisco ISE personas, see the Cisco ISE Admin Guide [\"https://www.cisco.com/c/en/us/td/docs/security/ise/3-3/admin_guide/b_ise_admin_3_3/b_ISE_admin_33_deployment.html#typesofpersonas\"].\r\n\r\nNote:\r\n\r\nIf PSNs are behind a load balancer, the exploit traffic can cascade across to other PSNs.\r\nIf PSN node groups are configured, the exploit traffic will not cascade across to other PSNs.\r\n\r\nRestart Cisco ISE\r\n\r\nTo stop and then start a Cisco ISE node from the CLI, use the following steps. For more details on each command, see the Cisco ISE CLI Reference Guide [\"https://www.cisco.com/c/en/us/td/docs/security/ise/3-3/cli_guide/b_ise_CLI_Reference_Guide_33/b_ise_CLIReferenceGuide_33_chapter_01.html\"].\r\n\r\nNote: During the restart period, any devices already authenticated will still be connected to the network. New authentications will not be processed unless PSN failover is configured.\r\n\r\nLog in to the affected PSN through the CLI.\r\nIssue the command application stop ise and wait for the prompt to return output, as shown in the following example:\r\n\r\nise/admin# application stop ise\r\nStopping ISE Monitoring & Troubleshooting Log Processor... PassiveID WMI Service is disabled PassiveID Syslog Service is disabled PassiveID API Service is disabled\r\n.\r\n.\r\n.\r\n\r\nise/admin#\r\n\r\nIssue the command application start ise and wait for the prompt to return output, as shown in the following example:\r\n\r\nise/admin# application start ise\r\nVerified OK\r\n\r\nISE Database processes already running, PID: 3310843\r\nStopping ISE Database processes...\r\nStarting ISE Messaging Service...\r\nStarting ISE API Gateway Database Service....\r\n.\r\n.\r\nise/admin#\r\n\r\n\r\nIssue the command show application status ise to see the status of the processes, as shown in the following example.\r\nNote: When the Application Server is running, authentications will take place and the node will be accessible through the GUI.\r\n\r\nise/admin# show application status ise\r\nISE PROCESS NAME STATE PROCESS ID -------------------------------------------------------------------- Database Listener running 3313832 Database Server running 92 PROCESSES Application Server running 3330909 Profiler Database running 3321522 ISE Indexing Engine running 3332725 .\r\n.\r\n.\r\nise/admin#\r\n\r\n\r\nPSN Failover Information\r\n\r\nFor PSN failover options, see the Policy Service Nodes and Node Groups section of this Cisco Press article [\"https://www.ciscopress.com/articles/article.asp?p=2812072&seqNum=2\"].\r\n\r\nFor information on how to configure node groups, see the Policy Service Node section [\"https://www.cisco.com/c/en/us/td/docs/security/ise/3-3/admin_guide/b_ise_admin_3_3/b_ISE_admin_33_deployment.html#ID64\"] of the Cisco ISE Admin Guide." }, { "category": "general", "title": "Workarounds", "text": "There are no workarounds that address this vulnerability. However, several potential mitigations may help address this vulnerability.\r\n\r\nTo mitigate this vulnerability, customers can turn off RADIUS accounting on the network access device (NAD) sending the crafted packets to the Cisco ISE PSN. There may be other mitigations for this vulnerability for customers who cannot upgrade to a fixed release. To coordinate implementation of the mitigations, contact the Cisco Technical Assistance Center (TAC) [\"https://www.cisco.com/go/tac/\"].\r\n\r\nWhile these mitigations have been deployed and were proven successful in a test environment, customers should determine the applicability and effectiveness in their own environment and under their own use conditions. Customers should be aware that any workaround or mitigation that is implemented may negatively impact the functionality or performance of their network based on intrinsic customer deployment scenarios and limitations. Customers should not deploy any workarounds or mitigations before first evaluating the applicability to their own environment and any impact to such environment." }, { "category": "general", "title": "Fixed Software", "text": "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.\r\n\r\nCustomers 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:\r\nhttps://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\"]\r\n\r\nAdditionally, 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.\r\n\r\nThe 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.\r\n\r\nWhen 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.\r\n\r\nIn 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.\r\n Customers Without Service Contracts\r\nCustomers 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\"]\r\n\r\nCustomers 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.\r\n Fixed Releases\r\nIn the following table, 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 [\"https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html#fixes\"] as indicated in this section.\r\n Cisco ISE Release First Fixed Release 2.7 and earlier Not vulnerable 3.0 Not vulnerable 3.1 3.1P7 3.2 3.2P3 3.3 Not vulnerable\r\nFor instructions on upgrading a device, see the Upgrade Guides located on the Cisco ISE support page [\"https://www.cisco.com/c/en/us/support/security/identity-services-engine/series.html\"].\r\n\r\nThe Cisco Product Security Incident Response Team (PSIRT) validates only the affected and fixed release information that is documented in this advisory." }, { "category": "general", "title": "Vulnerability Policy", "text": "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." }, { "category": "general", "title": "Exploitation and Public Announcements", "text": "The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory." }, { "category": "general", "title": "Source", "text": "This vulnerability was found during the resolution of a Cisco TAC support case." }, { "category": "legal_disclaimer", "title": "Legal Disclaimer", "text": "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.\r\n\r\nA standalone copy or paraphrase of the text of this document that omits the distribution URL is an uncontrolled copy and may lack important information or contain factual errors. The information in this document is intended for end users of Cisco products." } ], "publisher": { "category": "vendor", "contact_details": "psirt@cisco.com", "issuing_authority": "Cisco PSIRT", "name": "Cisco", "namespace": "https://wwww.cisco.com" }, "references": [ { "category": "self", "summary": "Cisco Identity Services Engine RADIUS Denial of Service Vulnerability", "url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ise-radius-dos-W7cNn7gt" }, { "category": "external", "summary": "Cisco Security Vulnerability Policy", "url": "https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html" }, { "category": "external", "summary": "Cisco ISE Admin Guide", "url": "https://www.cisco.com/c/en/us/td/docs/security/ise/3-3/admin_guide/b_ise_admin_3_3/b_ISE_admin_33_deployment.html#typesofpersonas" }, { "category": "external", "summary": "Cisco ISE CLI Reference Guide", "url": "https://www.cisco.com/c/en/us/td/docs/security/ise/3-3/cli_guide/b_ise_CLI_Reference_Guide_33/b_ise_CLIReferenceGuide_33_chapter_01.html" }, { "category": "external", "summary": "this Cisco Press article", "url": "https://www.ciscopress.com/articles/article.asp?p=2812072&seqNum=2" }, { "category": "external", "summary": "Policy Service Node section", "url": "https://www.cisco.com/c/en/us/td/docs/security/ise/3-3/admin_guide/b_ise_admin_3_3/b_ISE_admin_33_deployment.html#ID64" }, { "category": "external", "summary": "Cisco Technical Assistance Center (TAC)", "url": "https://www.cisco.com/go/tac/" }, { "category": "external", "summary": "free software updates", "url": "https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html#ssu" }, { "category": "external", "summary": "https://www.cisco.com/c/en/us/products/end-user-license-agreement.html", "url": "https://www.cisco.com/c/en/us/products/end-user-license-agreement.html" }, { "category": "external", "summary": "Cisco Support and Downloads page", "url": "https://www.cisco.com/c/en/us/support/index.html" }, { "category": "external", "summary": "considering software upgrades", "url": "https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html#fixes" }, { "category": "external", "summary": "Cisco Security Advisories page", "url": "https://www.cisco.com/go/psirt" }, { "category": "external", "summary": "https://www.cisco.com/c/en/us/support/web/tsd-cisco-worldwide-contacts.html", "url": "https://www.cisco.com/c/en/us/support/web/tsd-cisco-worldwide-contacts.html" }, { "category": "external", "summary": "Cisco ISE support page", "url": "https://www.cisco.com/c/en/us/support/security/identity-services-engine/series.html" }, { "category": "external", "summary": "Security Vulnerability Policy", "url": "http://www.cisco.com/web/about/security/psirt/security_vulnerability_policy.html" } ], "title": "Cisco Identity Services Engine RADIUS Denial of Service Vulnerability", "tracking": { "current_release_date": "2023-09-06T16:00:00+00:00", "generator": { "date": "2024-05-10T23:26:12+00:00", "engine": { "name": "TVCE" } }, "id": "cisco-sa-ise-radius-dos-W7cNn7gt", "initial_release_date": "2023-09-06T16:00:00+00:00", "revision_history": [ { "date": "2023-09-06T15:51:52+00:00", "number": "1.0.0", "summary": "Initial public release." } ], "status": "final", "version": "1.0.0" } }, "product_tree": { "branches": [ { "name": "Cisco", "category": "vendor", "branches": [ { "name": "Cisco Identity Services Engine Software", "category": "product_family", "product": { "name": "Cisco Identity Services Engine Software ", "product_id": "CSAFPID-111903" } } ] } ] }, "vulnerabilities": [ { "cve": "CVE-2023-20243", "ids": [ { "system_name": "Cisco Bug ID", "text": "CSCwe47081" } ], "notes": [ { "category": "other", "title": "Affected Product Comprehensiveness", "text": "Complete." } ], "product_status": { "known_affected": [ "CSAFPID-111903" ] }, "release_date": "2023-09-06T16:00:00+00:00", "remediations": [ { "category": "vendor_fix", "details": "Cisco has released software updates that address this vulnerability.", "product_ids": [ "CSAFPID-111903" ], "url": "https://software.cisco.com" } ], "scores": [ { "cvss_v3": { "baseScore": 8.6, "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H", "version": "3.1" }, "products": [ "CSAFPID-111903" ] } ], "title": "Cisco Identity Services Engine RADIUS Service Denial of Service Vulnerability" } ] }