cisco-sa-ioxr-l-znhcgcbt
Vulnerability from csaf_cisco
Published
2021-02-03 16:00
Modified
2021-02-03 16:00
Summary
Cisco IOS XR Software for Cisco 8000 Series Routers and Network Convergence System 540 Series Routers Image Verification Vulnerabilities

Notes

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 ["#details"] section of this advisory. Cisco has released software updates that address these vulnerabilities. There are no workarounds that address these vulnerabilities.
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 ["#fs"] 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 ["#vp"] 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 ["https://bst.cloudapps.cisco.com/bugsearch/bug/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 ["https://sec.cloudapps.cisco.com/security/center/cvssCalculator.x?version=3.1&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 ["https://bst.cloudapps.cisco.com/bugsearch/bug/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 ["https://sec.cloudapps.cisco.com/security/center/cvssCalculator.x?version=3.1&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 ["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 ["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. 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
Vulnerability Policy
To learn about Cisco security vulnerability disclosure policies and publications, see the Security Vulnerability Policy ["https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html"]. This document also contains instructions for obtaining fixed software and receiving security vulnerability information from Cisco.
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.
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.


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{
  "document": {
    "acknowledgments": [
      {
        "summary": "This vulnerability was found during internal security testing."
      }
    ],
    "category": "csaf_security_advisory",
    "csaf_version": "2.0",
    "notes": [
      {
        "category": "summary",
        "text": "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.\r\n\r\nFor more information about these vulnerabilities, see the Details [\"#details\"] section of this advisory.\r\n\r\nCisco has released software updates that address these vulnerabilities. There are no workarounds that address these vulnerabilities.\r\n\r\n",
        "title": "Summary"
      },
      {
        "category": "general",
        "text": "These vulnerabilities affect the following Cisco devices if they are running a vulnerable release of Cisco IOS XR Software:\r\n\r\n8000 Series Routers\r\nNCS 540 Series Routers that are running the NCS540L images\r\n\r\nFor information about which Cisco software releases are vulnerable, see the Fixed Software [\"#fs\"] section of this advisory.\r\n  Determine the Software Version\r\nTo 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.\r\n\r\n\r\nRouter#show version\r\nCisco IOS XR Software, Version 7.0.1 LNT\r\nCopyright (c) 2013-2019 by Cisco Systems, Inc.Build Information:",
        "title": "Vulnerable Products"
      },
      {
        "category": "general",
        "text": "Only products listed in the Vulnerable Products [\"#vp\"] section of this advisory are known to be affected by this vulnerability.",
        "title": "Products Confirmed Not Vulnerable"
      },
      {
        "category": "general",
        "text": "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.\r\n\r\nDetails about the vulnerabilities are as follows:\r\n\r\nCVE-2021-1136: Cisco IOS XR Software for Cisco 8000 Series Routers and Network Convergence System 540 Series Routers GRUB Boot Loader Vulnerability\r\n\r\nA 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.\r\n\r\nThe 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.\r\n\r\nCisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.\r\n\r\nBug ID(s): CSCvs70887 [\"https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvs70887\"]\r\nCVE ID: CVE-2021-1136\r\nSecurity Impact Rating (SIR): High\r\nCVSS Base Score: 6.7\r\nCVSS Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H [\"https://sec.cloudapps.cisco.com/security/center/cvssCalculator.x?version=3.1\u0026vector=CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H\"]\r\n\r\nCVE-2021-1244: Cisco IOS XR Software for Cisco 8000 Series Routers and Network Convergence System 540 Series Routers Unsigned Boot File Vulnerability\r\n\r\nA 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.\r\n\r\nThe 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.\r\n\r\nCisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.\r\n\r\nBug ID(s): CSCvr07463 [\"https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvr07463\"]\r\nCVE ID: CVE-2021-1244\r\nSecurity Impact Rating (SIR): High\r\nCVSS Base Score: 6.7\r\nCVSS Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H [\"https://sec.cloudapps.cisco.com/security/center/cvssCalculator.x?version=3.1\u0026vector=CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H\"]",
        "title": "Details"
      },
      {
        "category": "general",
        "text": "There are no workarounds that address these vulnerabilities.",
        "title": "Workarounds"
      },
      {
        "category": "general",
        "text": "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:\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\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\nThe following table shows the first fixed release for each CVE ID:\r\n        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\r\n7.2.1  7.0.14\r\n7.2.1      Cisco NCS 540 Series Routers  7.2.1  7.1.2\r\n7.2.1",
        "title": "Fixed Software"
      },
      {
        "category": "general",
        "text": "To learn about Cisco security vulnerability disclosure policies and publications, see the Security Vulnerability Policy [\"https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html\"]. This document also contains instructions for obtaining fixed software and receiving security vulnerability information from Cisco.",
        "title": "Vulnerability Policy"
      },
      {
        "category": "general",
        "text": "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.",
        "title": "Exploitation and Public Announcements"
      },
      {
        "category": "general",
        "text": "This vulnerability was found during internal security testing.",
        "title": "Source"
      },
      {
        "category": "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.",
        "title": "Legal Disclaimer"
      }
    ],
    "publisher": {
      "category": "vendor",
      "contact_details": "psirt@cisco.com",
      "issuing_authority": "Cisco PSIRT",
      "name": "Cisco",
      "namespace": "https://wwww.cisco.com"
    },
    "references": [
      {
        "category": "self",
        "summary": "Cisco IOS XR Software for Cisco 8000 Series Routers and Network Convergence System 540 Series Routers Image Verification Vulnerabilities",
        "url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ioxr-l-zNhcGCBt"
      },
      {
        "category": "external",
        "summary": "Cisco Security Vulnerability Policy",
        "url": "https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html"
      },
      {
        "category": "external",
        "summary": "CSCvs70887",
        "url": "https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvs70887"
      },
      {
        "category": "external",
        "summary": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H",
        "url": "https://sec.cloudapps.cisco.com/security/center/cvssCalculator.x?version=3.1\u0026amp;vector=CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H"
      },
      {
        "category": "external",
        "summary": "CSCvr07463",
        "url": "https://bst.cloudapps.cisco.com/bugsearch/bug/CSCvr07463"
      },
      {
        "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": "considering software upgrades",
        "url": "https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html#fixes"
      },
      {
        "category": "external",
        "summary": "Cisco\u0026nbsp;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"
      }
    ],
    "title": "Cisco IOS XR Software for Cisco 8000 Series Routers and Network Convergence System 540 Series Routers Image Verification Vulnerabilities",
    "tracking": {
      "current_release_date": "2021-02-03T16:00:00+00:00",
      "generator": {
        "date": "2024-05-10T22:59:20+00:00",
        "engine": {
          "name": "TVCE"
        }
      },
      "id": "cisco-sa-ioxr-l-zNhcGCBt",
      "initial_release_date": "2021-02-03T16:00:00+00:00",
      "revision_history": [
        {
          "date": "2021-02-03T15:00:58+00:00",
          "number": "1.0.0",
          "summary": "Initial public release."
        }
      ],
      "status": "final",
      "version": "1.0.0"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "category": "product_family",
            "name": "Cisco IOS XR Software",
            "product": {
              "name": "Cisco IOS XR Software ",
              "product_id": "CSAFPID-5834"
            }
          }
        ],
        "category": "vendor",
        "name": "Cisco"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2021-1244",
      "ids": [
        {
          "system_name": "Cisco Bug ID",
          "text": "CSCvr07463"
        }
      ],
      "notes": [
        {
          "category": "other",
          "text": "Complete.",
          "title": "Affected Product Comprehensiveness"
        }
      ],
      "product_status": {
        "known_affected": [
          "CSAFPID-5834"
        ]
      },
      "release_date": "2021-02-03T16:00:00+00:00",
      "remediations": [
        {
          "category": "vendor_fix",
          "details": "Cisco has released software updates that address this vulnerability.",
          "product_ids": [
            "CSAFPID-5834"
          ],
          "url": "https://software.cisco.com"
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "baseScore": 6.7,
            "baseSeverity": "MEDIUM",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "products": [
            "CSAFPID-5834"
          ]
        }
      ],
      "title": "Cisco IOS XR Software for Network Convergence System 540 Series Routers Image Verification Vulnerability"
    },
    {
      "cve": "CVE-2021-1136",
      "notes": [
        {
          "category": "other",
          "text": "Not available.",
          "title": "Affected Product Comprehensiveness"
        }
      ],
      "release_date": "2021-02-03T16:00:00+00:00",
      "title": "Cisco IOS-XR Secure Boot Bypass on Spitfire"
    }
  ]
}


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  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
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