==================================================================== CERT-Renater Note d'Information No. 2021/VULN070 _____________________________________________________________________ DATE : 04/02/2021 HARDWARE PLATFORM(S): / OPERATING SYSTEM(S): Cisco IOS XR Software versions prior to 6.7.3, 7.1.3, 7.2.2, 7.3.1. ===================================================================== https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-pe-QpzCAePe https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-xripv6-spJem78K https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ioxr-l-zNhcGCBt https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-dos-WwDdghs2 _____________________________________________________________________ Cisco IOS XR Software for Cisco 8000 Series Routers and Network Convergence System 540 Series Routers Privilege Escalation Vulnerability High Advisory ID: cisco-sa-iosxr-pe-QpzCAePe First Published: 2021 February 3 16:00 GMT Version 1.0: Final Workarounds: No workarounds available Cisco Bug IDs: CSCvs35027 CVSS Score: Base 7.8 CVE-2021-1370 CWE-78 Summary A vulnerability in a CLI command of Cisco IOS XR Software for the Cisco 8000 Series Routers and Network Convergence System 540 Series Routers running NCS540L software images could allow an authenticated, local attacker to elevate their privilege to root. To exploit this vulnerability, an attacker would need to have a valid account on an affected device. The vulnerability is due to insufficient validation of command line arguments. An attacker could exploit this vulnerability by authenticating to the device and entering a crafted command at the prompt. A successful exploit could allow an attacker with low-level privileges to escalate their privilege level to root. 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://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-pe-QpzCAePe Affected Products Vulnerable Products This vulnerability affects Cisco IOS XR Software on the following platforms: Cisco 8000 Series Routers if running releases earlier than the first fixed release. Network Convergence System 540 Series Routers 7.x releases if running releases earlier than the first fixed software release and running the NCS540L images. Determine the Software Version To determine if the device is running an NCS540L image, administrators can log into the device and issue the show version command. If the output indicates LNT then it is running on an affected device. Router#show version Cisco IOS XR Software, Version 7.0.1 LNT Copyright (c) 2013-2019 by Cisco Systems, Inc. Build Information: Built By : xyz Built On : Sat Jun 29 22:45:27 2019 Build Host : iox-lnx-064 Workspace : ../7.0.1/NCS540L/ws/ Version : 7.0.1 Label : 7.0.1 cisco NCS540L System uptime is 41 minutes Products Confirmed Not Vulnerable Only products listed in the Vulnerable Products section of this advisory are known to be affected by this vulnerability. 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 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. 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 Customers are advised to upgrade to an appropriate fixed software release as indicated in the following table(s): Platform Cisco IOS XR Software Release Cisco 8000 Series Routers 7.0.12 7.2.1 Network Convergence System 540 Series Routers 7.2.1 Cisco has released software maintenance upgrades (SMUs) to address this vulnerability. Customers who require SMUs for other platforms and releases are advised to contact their support organization. Cisco IOS XR Software Release Platform SMU Name 7.1.2 NCS540L ncs540l-7.1.2.CSCvs35027 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. Source This vulnerability was found during internal security testing. URL https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-pe-QpzCAePe Revision History Version Description Section Status Date 1.0 Initial public release. — Final 2021-FEB-03 Legal Disclaimer 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 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. _____________________________________________________________________ Cisco IOS XR Software IPv6 Flood Denial of Service Vulnerability High Advisory ID: cisco-sa-xripv6-spJem78K First Published: 2021 February 3 16:00 GMT Version 1.0: Final Workarounds: Yes Cisco Bug IDs: CSCvv45504 CVSS Score: Base 7.4 CVE-2021-1268 CWE-1076 Summary A vulnerability in the IPv6 protocol handling of the management interfaces of Cisco IOS XR Software could allow an unauthenticated, adjacent attacker to cause an IPv6 flood on the management interface network of an affected device. The vulnerability exists because the software incorrectly forwards IPv6 packets that have an IPv6 node-local multicast group address destination and are received on the management interfaces. An attacker could exploit this vulnerability by connecting to the same network as the management interfaces and injecting IPv6 packets that have an IPv6 node-local multicast group address destination. A successful exploit could allow the attacker to cause an IPv6 flood on the corresponding network. Depending on the number of Cisco IOS XR Software nodes on that network segment, exploitation could cause excessive network traffic, resulting in network degradation or a denial of service (DoS) condition. Cisco has released software updates that address this vulnerability. There are workarounds that address this vulnerability. This advisory is available at the following link: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-xripv6-spJem78K Affected Products Vulnerable Products This vulnerability affects Cisco devices if they are running a vulnerable release of Cisco IOS XR Software and the management interface is configured with both of the following: An IPv6 address The default IPv6 static route with next-hop on the management interface segment For information about which Cisco software releases are vulnerable, see the Fixed Software section of this advisory. Products Confirmed Not Vulnerable Only products listed in the Vulnerable Products section of this advisory are known to be affected by this vulnerability. Details If this vulnerability is exploited, the number of packets that are forwarded to the network is dependent on the number of Cisco IOS XR Software management interfaces that are connected to the network segment. The more Cisco IOS XR devices that have management interfaces and are connected to the same Layer 2 domain, the more packets that are forwarded on the Layer 2 segment. An excessive number of forwarded packets could result in network degradation and possibly cause a denial of service (DoS) condition on the network. Workarounds Removing the default IPv6 static route and adding a prefix-specific route would mitigate this vulnerability. For example, removing the default IPv6 static route and adding an IPv6 static route of 2000::/3 would mitigate this vulnerability. Fixed Software Cisco has released free software updates that address the vulnerability described in this advisory. 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. 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 Cisco fixed this vulnerability in Cisco IOS XR Software releases 6.7.3, 7.1.3, 7.2.2, and 7.3.1. Cisco has released software maintenance upgrades (SMUs) to address this vulnerability. Customers who require SMUs for other platforms and releases are advised to contact their support organization. Cisco IOS XR Software Release Platform SMU Name 6.3.1 NCS1K ncs1k-6.3.1.CSCvv45504 NCS1001 ncs1001-6.3.1.CSCvv45504 6.5.2 NCS1K ncs1k-6.5.2.CSCvv45504 NCS1001 ncs1001-6.5.2.CSCvv45504 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. Source This vulnerability was found during the resolution of a Cisco TAC support case. URL https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-xripv6-spJem78K Revision History Version Description Section Status Date 1.0 Initial public release. — Final 2021-FEB-03 Legal Disclaimer 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 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. _____________________________________________________________________ Cisco IOS XR Software for Cisco 8000 Series Routers and Network Convergence System 540 Series Routers Image Verification Vulnerabilities High Advisory ID: cisco-sa-ioxr-l-zNhcGCBt First Published: 2021 February 3 16:00 GMT Version 1.0: Final Workarounds: No workarounds available Cisco Bug IDs: CSCvr07463 CSCvs70887 CVSS Score: Base 6.7 CVE-2021-1136 CVE-2021-1244 CWE-347 Summary Multiple vulnerabilities in Cisco Network Convergence System (NCS) 540 Series Routers, only when running Cisco IOS XR NCS540L software images, and Cisco IOS XR Software for the Cisco 8000 Series Routers could allow an authenticated, local attacker to execute unsigned code during the boot process on an affected device. For more information about these vulnerabilities, see the Details section of this advisory. Cisco has released software updates that address these vulnerabilities. There are no workarounds that address these vulnerabilities. This advisory is available at the following link: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ioxr-l-zNhcGCBt Affected Products Vulnerable Products These vulnerabilities affect the following Cisco devices if they are running a vulnerable release of Cisco IOS XR Software: 8000 Series Routers NCS 540 Series Routers that are running the NCS540L images For information about which Cisco software releases are vulnerable, see the Fixed Software section of this advisory. Determine the Software Version To determine whether the device is running an NCS540L software image, log in to the device and issue the show version command. If the output indicates LNT, as shown in the following example, then the device is affected by these vulnerabilities. Router#show version Cisco IOS XR Software, Version 7.0.1 LNT Copyright (c) 2013-2019 by Cisco Systems, Inc.Build Information: Products Confirmed Not Vulnerable Only products listed in the Vulnerable Products section of this advisory are known to be affected by this vulnerability. Details The vulnerabilities are not dependent on one another. Exploitation of one of the vulnerabilities is not required to exploit the other vulnerability. In addition, a software release that is affected by one of the vulnerabilities may not be affected by the other vulnerability. Details about the vulnerabilities are as follows: CVE-2021-1136: Cisco IOS XR Software for Cisco 8000 Series Routers and Network Convergence System 540 Series Routers GRUB Boot Loader Vulnerability A vulnerability in the GRUB boot loader of Cisco NCS 540 Series Routers, only when running Cisco IOS XR NCS540L software images, and Cisco IOS XR Software for the Cisco 8000 Series Routers could allow an authenticated, local attacker to execute unsigned code during the boot process on an affected device. The vulnerability is due to an unlocked version of GRUB boot loader on an affected device. An attacker could exploit this vulnerability by modifying the boot process from the GRUB menu. A successful exploit could allow the attacker to bypass the boot chain of trust. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. Bug ID(s): CSCvs70887 CVE ID: CVE-2021-1136 Security Impact Rating (SIR): High CVSS Base Score: 6.7 CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H CVE-2021-1244: Cisco IOS XR Software for Cisco 8000 Series Routers and Network Convergence System 540 Series Routers Unsigned Boot File Vulnerability A vulnerability in the signing functions of ISO packaging of Cisco NCS 540 Series Routers, only when running Cisco IOS XR NCS540L software images, and Cisco IOS XR Software for the Cisco 8000 Series Routers could allow an authenticated, local attacker with administrator privileges to execute unsigned code during the installation of an ISO on an affected device. The vulnerability is due to an unsigned script within the ISO that is not verified during system upgrade before it is executed. To exploit this vulnerability, an attacker could modify an ISO image and then either use that image to upgrade as an authenticated administrator or place that image on a file server, which an unsuspecting administrator could then use when upgrading the device. A successful exploit could allow the attacker to execute arbitrary code on the affected device. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. Bug ID(s): CSCvr07463 CVE ID: CVE-2021-1244 Security Impact Rating (SIR): High CVSS Base Score: 6.7 CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H Workarounds There are no workarounds that address these vulnerabilities. Fixed Software Cisco has released free software updates that address the vulnerability described in this advisory. 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. 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 The following table shows the first fixed release for each CVE ID: Affected Platform First Fixed Release for CVE-2021-1136 (CSCvs70887) First Fixed Release for CVE-2021-1244 (CSCvr07463) Cisco 8000 Series Routers 7.0.12 7.2.1 7.0.14 7.2.1 Cisco NCS 540 Series Routers 7.2.1 7.1.2 7.2.1 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. Source This vulnerability was found during internal security testing. URL https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ioxr-l-zNhcGCBt Revision History Version Description Section Status Date 1.0 Initial public release. — Final 2021-FEB-03 Legal Disclaimer 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 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. _____________________________________________________________________ Cisco IOS XR Software Enf Broker Denial of Service Vulnerability High Advisory ID: cisco-sa-iosxr-dos-WwDdghs2 First Published: 2021 February 3 16:00 GMT Version 1.0: Final Workarounds: No workarounds available Cisco Bug IDs: CSCuy67256 CSCuz39742 CVSS Score: Base 8.6 CVE-2021-1288 CVE-2021-1313 CWE-399 Summary Multiple vulnerabilities in the ingress packet processing function of Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. For more information about these vulnerabilities, see the Details section of this advisory. Cisco has released software updates that address these vulnerabilities. There are no workarounds that address these vulnerabilities. This advisory is available at the following link: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-dos-WwDdghs2 Affected Products Vulnerable Products These vulnerabilities affect Cisco devices if they are running an affected release of Cisco IOS XR Software. For information about which Cisco software releases are vulnerable, see the Fixed Software section of this advisory. Products Confirmed Not Vulnerable Only products listed in the Vulnerable Products section of this advisory are known to be affected by these vulnerabilities. Cisco has confirmed that these vulnerabilities do not affect the following Cisco products: IOS Software IOS XE Software NX-OS Software Details The vulnerabilities are not dependent on one another. Exploitation of one of the vulnerabilities is not required to exploit the other vulnerability. In addition, a software release that is affected by one of the vulnerabilities may not be affected by the other vulnerability. Details about the vulnerabilities are as follows. CVE-2021-1288: Cisco IOS XR Software Enf Broker Denial of Service Vulnerability A vulnerability in the ingress packet processing function of Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause a DoS condition on an affected device. The vulnerability is due to a logic error that occurs when an affected device processes Telnet protocol packets. An attacker could exploit this vulnerability by sending specific streams of packets to the affected device. A successful exploit could allow the attacker to cause the enf_broker process to crash, which could lead to system instability and the inability to process or forward traffic through the affected device. This vulnerability can be exploited using specific, crafted streams of packets over either IPv4 or IPv6. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. Bug ID(s): CSCuz39742 CVE ID: CVE-2021-1288 Security Impact Rating (SIR): High CVSS Base Score: 8.6 CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H CVE-2021-1313: Cisco IOS XR Software Enf Broker Denial of Service Vulnerability A vulnerability in the ingress packet processing function of Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause a DoS condition on an affected device. The vulnerability is due to improper resource allocation when an affected device processes either ICMP or Telnet protocol packets. An attacker could exploit this vulnerability by sending specific streams of packets to the affected device. A successful exploit could allow the attacker to cause the enf_broker process to leak system memory. Over time, this memory leak could cause the enf_broker process to crash, which could lead to system instability and the inability to process or forward traffic through the affected device. This vulnerability can be exploited using specific, crafted streams of packets over either IPv4 or IPv6. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. Bug ID(s): CSCuy67256 CVE ID: CVE-2021-1313 Security Impact Rating (SIR): High CVSS Base Score: 8.6 CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H Indicators of Compromise Exploitation of either of these vulnerabilities can result in a crash of the enf_broker process on an affected device. When a device has experienced a crash of the enf_broker process, the following messages may be seen in the system logs: %OS-SYSMGR-3-ERROR : enf_broker(1) (jid 209) exited, will be respawned with a delay (slow-restart) %OS-SYSMGR-3-ERROR : enf_broker(209) (fail count 28597) will be respawned in 120 seconds %OS-DUMPER-7-DUMP_REQUEST : Dump request for process pkg/bin/enf_broker%OS-DUMPER-7-DUMP_ATTRIBUTE : Dump request with attribute 200 for process pkg/bin/enf_broker These error messages indicate that the enf_broker process has crashed. However, the process may have crashed for a reason other than the exploitation of one of these vulnerabilities. Customers are advised to contact their support organization to review the error messages and determine whether the device has been compromised by an exploitation of one of these vulnerabilities. Workarounds There are no workarounds for these vulnerabilities. However, multiple mitigations are available. As a mitigation for CVE-2021-1288, customers can disable the Telnet protocol for incoming connections. Information on how to disable Telnet can be found in the Cisco Guide to Harden Cisco IOS XR Devices. Because CVE-2021-1313 can be exploited when processing a stream of either Telnet or ICMP protocol packets, the following steps for mitigation should be implemented together to ensure protection against the two attack vectors: Disable the Telnet protocol for incoming connections. Implement an access control entry (ACE) to an existing interface ACL or create a new ACL that denies ICMP traffic that is inbound to a specific interface. The following input is an example of how to create an IPv4 ACL and deny ICMP traffic: P/0/0/CPU0:router(config)# ipv4 access-list deny icmp any any For information on how to perform both of these mitigations, see the Cisco Guide to Harden Cisco IOS XR Devices. While these mitigations have been deployed and were proven successful in a test environment, customers should determine the applicability and effectiveness on 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 their applicability to their own environment and any impact to such environment. Fixed Software Cisco has released free software updates that address the vulnerabilities described in this advisory. 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. 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 Customers are advised to upgrade to an appropriate fixed software release as indicated in the following table(s): Cisco IOS XR Software Release First Fixed Release for CVE-2021-1288 (CSCuz39742) First Fixed Release for CVE-2021-1313 (CSCuy67256) First Fixed Release for All Vulnerabilities Described in This Advisory 5.0 Migrate to a fixed release. 5.2.471 5.3.4 None. Apply SMU. 6.0 6.0.2 Not vulnerable. 6.0.2 7.0 and later Not vulnerable. Not vulnerable. Not vulnerable. 1Cisco IOS XR Software Release 5.2.47 addresses CVE-2021-1313 on Cisco Network Convergence System 4000 Series. For all other affected platforms that are running Cisco IOS XR, Cisco has fixed CVE-2021-1313 on Cisco IOS XR 5.3.4 software release and later. Cisco has released SMUs that address these vulnerabilities. The following tables provide the SMU name for each release based on platform. Although names of the SMUs include CSCuy67256 only, the SMUs contain the fixes for both CSCuz39742 and CSCuy67256. Cisco IOS XR Software Release Platform SMU Name 5.1.3 ASR9K-PX asr9k-px-5.1.3.CSCuy67256 5.3.2 ASR9K-PX asr9k-px-5.3.2.CSCuy67256 5.3.3 ASR9K-PX asr9k-px-5.3.3.CSCuy67256 CRS-PX hfr-px-5.3.3.CSCuy67256 Exploitation and Public Announcements The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerabilities that are described in this advisory. Source CVE-2021-1288: Cisco would like to thank the U.S. National Security Agency (NSA) for reporting this vulnerability. CVE-2021-1313: This vulnerability was found during the resolution of a Cisco TAC support case. URL https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-dos-WwDdghs2 Revision History Version Description Section Status Date 1.0 Initial public release. — Final 2021-FEB-03 Legal Disclaimer 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 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. ========================================================= + CERT-RENATER | tel : 01-53-94-20-44 + + 23/25 Rue Daviel | fax : 01-53-94-20-41 + + 75013 Paris | email:cert@support.renater.fr + =========================================================