cisco-sa-iosxr-dhcp-dos-3tgpkrdm
Vulnerability from csaf_cisco
Published
2024-03-13 16:00
Modified
2024-03-13 16:00
Summary
Cisco IOS XR Software DHCP Version 4 Server Denial of Service Vulnerability

Notes

Summary
A vulnerability in the DHCP version 4 (DHCPv4) server feature of Cisco IOS XR Software could allow an unauthenticated, remote attacker to trigger a crash of the dhcpd process, resulting in a denial of service (DoS) condition. This vulnerability exists because certain DHCPv4 messages are improperly validated when they are processed by an affected device. An attacker could exploit this vulnerability by sending a malformed DHCPv4 message to an affected device. A successful exploit could allow the attacker to cause a crash of the dhcpd process. While the dhcpd process is restarting, which may take approximately two minutes, DHCPv4 server services are unavailable on the affected device. This could temporarily prevent network access to clients that join the network during that time period and rely on the DHCPv4 server of the affected device. Notes: Only the dhcpd process crashes and eventually restarts automatically. The router does not reload. This vulnerability only applies to DHCPv4. DHCP version 6 (DHCPv6) is not affected. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is part of the March 2024 release of the Cisco IOS XR Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see Cisco Event Response: March 2024 Semiannual Cisco IOS XR Software Security Advisory Bundled Publication ["https://sec.cloudapps.cisco.com/security/center/viewErp.x?alertId=ERP-75299"].
Vulnerable Products
At the time of publication, this vulnerability affected Cisco IOS XR Software if it had the DHCPv4 server feature or the DHCPv4 proxy feature enabled. For information about which Cisco software releases were vulnerable at the time of publication, see the Fixed Software ["#fs"] section of this advisory. See the Details section in the bug ID(s) at the top of this advisory for the most complete and current information. Determine the DHCPv4 Configuration To determine whether the DHCPv4 server feature or the DHCPv4 proxy feature is enabled on a device, run the show running-config dhcp ipv4 command in privileged EXEC mode on the device CLI and check for a server profile that is either directly or indirectly (through a base profile) bound to at least one interface. The following example shows the output of the show running-config dhcp ipv4 command on a device that has the DHCPv4 server profile TEST directly bound to interface GigabitEthernet0/0/0/0: dhcp ipv4 profile TEST server . . . ! interface GigabitEthernet0/0/0/0 server profile TEST The following example shows the output of the show running-config dhcp ipv4 command on a device that has the DHCPv4 server profiles DHCP_SERVER and DEFAULT_PROFILE indirectly bound to interface GigabitEthernet0/0/0/0 through base profile DHCP_BASE: dhcp ipv4 profile DHCP_BASE base match option 60 41424355 profile DHCP_SERVER server default profile DEFAULT_PROFILE server . . . ! profile DHCP_SERVER server . . . ! profile DEFAULT_PROFILE server . . . ! interface GigabitEthernet0/0/0/0 base profile DHCP_BASE The following example shows the output of the show running-config dhcp ipv4 command on a device that has the DHCPv4 proxy profile PROXY directly bound to interface GigabitEthernet0/0/0/0: dhcp ipv4 profile PROXY proxy helper-address vrf default 192.168.23.7 giaddr 192.168.23.11 ! interface GigabitEthernet0/0/0/0 proxy profile PROXY
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 Software IOS XE Software NX-OS Software
Workarounds
There are no workarounds that address this vulnerability.
Fixed Software
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. Fixed Releases At the time of publication, the release information in the following table was accurate. See the Details section in the bug ID(s) at the top of this advisory for the most complete and current information. The left column lists Cisco software releases, and the right column indicates whether a release was affected by the vulnerability that is described in this advisory and which release included the fix for this vulnerability. Cisco IOS XR Software Release First Fixed Release 7.9 and earlier Migrate to a fixed release. 7.10 Migrate to a fixed release. 7.11 7.11.1 24.1 24.1.1 The Cisco Product Security Incident Response Team (PSIRT) validates only the affected and fixed release information that is documented in this advisory.
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.
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 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": "A vulnerability in the DHCP version 4 (DHCPv4) server feature of Cisco IOS XR Software could allow an unauthenticated, remote attacker to trigger a crash of the dhcpd process, resulting in a denial of service (DoS) condition.\r\n\r\nThis vulnerability exists because certain DHCPv4 messages are improperly validated when they are processed by an affected device. An attacker could exploit this vulnerability by sending a malformed DHCPv4 message to an affected device. A successful exploit could allow the attacker to cause a crash of the dhcpd process. While the dhcpd process is restarting, which may take approximately two minutes, DHCPv4 server services are unavailable on the affected device. This could temporarily prevent network access to clients that join the network during that time period and rely on the DHCPv4 server of the affected device.\r\n\r\nNotes:\r\n\r\nOnly the dhcpd process crashes and eventually restarts automatically. The router does not reload.\r\nThis vulnerability only applies to DHCPv4. DHCP version 6 (DHCPv6) is not affected.\r\n\r\nCisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.\r\n\r\n\r\n\r\nThis advisory is part of the March 2024 release of the Cisco IOS XR Software Security Advisory Bundled Publication. For a complete list of the advisories and links to them, see Cisco Event Response: March 2024 Semiannual Cisco IOS XR Software Security Advisory Bundled Publication [\"https://sec.cloudapps.cisco.com/security/center/viewErp.x?alertId=ERP-75299\"].",
        "title": "Summary"
      },
      {
        "category": "general",
        "text": "At the time of publication, this vulnerability affected Cisco IOS XR Software if it had the DHCPv4 server feature or the DHCPv4 proxy feature enabled.\r\n\r\nFor information about which Cisco software releases were vulnerable at the time of publication, see the Fixed Software [\"#fs\"] section of this advisory. See the Details section in the bug ID(s) at the top of this advisory for the most complete and current information.\r\n  Determine the DHCPv4 Configuration\r\nTo determine whether the DHCPv4 server feature or the DHCPv4 proxy feature is enabled on a device, run the show running-config dhcp ipv4 command in privileged EXEC mode on the device CLI and check for a server profile that is either directly or indirectly (through a base profile) bound to at least one interface.\r\n\r\nThe following example shows the output of the show running-config dhcp ipv4 command on a device that has the DHCPv4 server profile TEST directly bound to interface GigabitEthernet0/0/0/0:\r\n\r\n\r\ndhcp ipv4\r\nprofile TEST server\r\n.\r\n.\r\n.\r\n!\r\ninterface GigabitEthernet0/0/0/0 server profile TEST\r\n\r\nThe following example shows the output of the show running-config dhcp ipv4 command on a device that has the DHCPv4 server profiles DHCP_SERVER and DEFAULT_PROFILE indirectly bound to interface GigabitEthernet0/0/0/0 through base profile DHCP_BASE:\r\n\r\n\r\ndhcp ipv4\r\nprofile DHCP_BASE base\r\nmatch option 60 41424355 profile DHCP_SERVER server\r\ndefault profile DEFAULT_PROFILE server\r\n.\r\n.\r\n.\r\n!\r\nprofile DHCP_SERVER server\r\n.\r\n.\r\n.\r\n!\r\nprofile DEFAULT_PROFILE server\r\n.\r\n.\r\n.\r\n!\r\ninterface GigabitEthernet0/0/0/0 base profile DHCP_BASE\r\n\r\nThe following example shows the output of the show running-config dhcp ipv4 command on a device that has the DHCPv4 proxy profile PROXY directly bound to interface GigabitEthernet0/0/0/0:\r\n\r\n\r\ndhcp ipv4\r\nprofile PROXY proxy\r\nhelper-address vrf default 192.168.23.7 giaddr 192.168.23.11\r\n!\r\ninterface GigabitEthernet0/0/0/0 proxy profile PROXY",
        "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.\r\n\r\nCisco has confirmed that this vulnerability does not affect the following Cisco products:\r\n\r\nIOS Software\r\nIOS XE Software\r\nNX-OS Software",
        "title": "Products Confirmed Not Vulnerable"
      },
      {
        "category": "general",
        "text": "There are no workarounds that address this vulnerability.",
        "title": "Workarounds"
      },
      {
        "category": "general",
        "text": "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.\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      Fixed Releases\r\nAt the time of publication, the release information in the following table was accurate. See the Details section in the bug ID(s) at the top of this advisory for the most complete and current information.\r\n\r\nThe left column lists Cisco software releases, and the right column indicates whether a release was affected by the vulnerability that is described in this advisory and which release included the fix for this vulnerability.\r\n        Cisco IOS XR Software Release  First Fixed Release          7.9 and earlier  Migrate to a fixed release.      7.10  Migrate to a fixed release.      7.11  7.11.1      24.1  24.1.1\r\nThe Cisco Product Security Incident Response Team (PSIRT) validates only the affected and fixed release information that is documented in this advisory.",
        "title": "Fixed Software"
      },
      {
        "category": "general",
        "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.",
        "title": "Vulnerability Policy"
      },
      {
        "category": "general",
        "text": "The Cisco 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 DHCP Version 4 Server Denial of Service Vulnerability",
        "url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-dhcp-dos-3tgPKRdm"
      },
      {
        "category": "external",
        "summary": "Cisco Event Response: March 2024 Semiannual Cisco IOS XR Software Security Advisory Bundled Publication",
        "url": "https://sec.cloudapps.cisco.com/security/center/viewErp.x?alertId=ERP-75299"
      },
      {
        "category": "external",
        "summary": "Cisco Security Vulnerability Policy",
        "url": "https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.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": "Security Vulnerability Policy",
        "url": "http://www.cisco.com/web/about/security/psirt/security_vulnerability_policy.html"
      }
    ],
    "title": "Cisco IOS XR Software DHCP Version 4 Server Denial of Service Vulnerability",
    "tracking": {
      "current_release_date": "2024-03-13T16:00:00+00:00",
      "generator": {
        "date": "2024-05-10T23:29:34+00:00",
        "engine": {
          "name": "TVCE"
        }
      },
      "id": "cisco-sa-iosxr-dhcp-dos-3tgPKRdm",
      "initial_release_date": "2024-03-13T16:00:00+00:00",
      "revision_history": [
        {
          "date": "2024-03-13T15:56:37+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-2024-20266",
      "ids": [
        {
          "system_name": "Cisco Bug ID",
          "text": "CSCwf83090"
        }
      ],
      "notes": [
        {
          "category": "other",
          "text": "Complete.",
          "title": "Affected Product Comprehensiveness"
        }
      ],
      "product_status": {
        "known_affected": [
          "CSAFPID-5834"
        ]
      },
      "release_date": "2024-03-13T16:00:00+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": 5.3,
            "baseSeverity": "MEDIUM",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
            "version": "3.1"
          },
          "products": [
            "CSAFPID-5834"
          ]
        }
      ],
      "title": "Cisco IOS XR Software DHCP Version 4 Server Denial of Service Vulnerability"
    }
  ]
}


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