CVE-2026-121367 (GCVE-0-2026-121367)

Vulnerability from cvelistv5 – Published: 2026-11-10 20:10 – Updated: 2026-11-10 20:10
VLAI
Title
Security Advisory 0220
Summary
On affected Arista EOS platforms with Routing Information Protocol version 2 (RIPv2) configured, under certain conditions, RIPv2 might be silently enabled on management interfaces even when the RIP agent intends to disable it. It allows an unauthenticated attacker with access to the adjacent network to send crafted RIPv2 route advertisements to the device's management IP address. The device could accept and install those routes without authentication. Successful exploitation could allow the attacker to redirect traffic flows to an attacker-controlled destination, install more-specific routes that blackhole legitimate traffic, or otherwise disrupt network reachability for systems whose traffic passes through the affected device.
Severity
9.6 (Critical)
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:H
6.1 (Medium)
CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:H/SC:N/SI:L/SA:L
CWE
  • CWE-440 - Expected Behavior Violation
Assigner
Arista CNA under the mitre root
CNA scorecard B 87/100 over 116 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Arista Networks EOS Affected: 1.0.0 , < 4.33.0F (custom)
Affected: 4.33.0F , ≤ 4.33.10M (custom)
Affected: 4.34.0F , ≤ 4.34.8M (custom)
Affected: 4.35.0F , ≤ 4.35.6M (custom)
Affected: 4.36.0F , ≤ 4.36.2F (custom)
Affected: 4.37.0F (custom)
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "platforms": [
            "710 Series",
            "720D Series",
            "720XP/722XPM Series",
            "750X Series",
            "7010TX Series",
            "7020R/R4 Series",
            "7130 Series running EOS",
            "7170 Series",
            "7050X3/X4 Series",
            "7060X/X2/X4/X5/X6/XE7 Series",
            "7260X/X3 Series",
            "7280R/R2/R3/R4 Series",
            "7300X/X3 Series",
            "7320X Series",
            "7358X4 Series",
            "7368X4 Series",
            "7388X5 Series",
            "7500R/R2/R3 Series",
            "7800R3/R4 Series",
            "7700R4 Series",
            "AWE 5000 Series",
            "AWE 7200R Series",
            "ZTX-7200 Series",
            "CloudEOS",
            "cEOS-lab",
            "vEOS-lab",
            "CloudVision eXchange, virtual or physical appliance"
          ],
          "product": "EOS",
          "vendor": "Arista Networks",
          "versions": [
            {
              "lessThan": "4.33.0F",
              "status": "affected",
              "version": "1.0.0",
              "versionType": "custom"
            },
            {
              "lessThanOrEqual": "4.33.10M",
              "status": "affected",
              "version": "4.33.0F",
              "versionType": "custom"
            },
            {
              "lessThanOrEqual": "4.34.8M",
              "status": "affected",
              "version": "4.34.0F",
              "versionType": "custom"
            },
            {
              "lessThanOrEqual": "4.35.6M",
              "status": "affected",
              "version": "4.35.0F",
              "versionType": "custom"
            },
            {
              "lessThanOrEqual": "4.36.2F",
              "status": "affected",
              "version": "4.36.0F",
              "versionType": "custom"
            },
            {
              "status": "affected",
              "version": "4.37.0F",
              "versionType": "custom"
            }
          ]
        }
      ],
      "configurations": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "\u003cpre\u003eswitch# show running-config section router rip\nrouter rip\n   network 10.252.36.128/25\n   no shutdown\n\nswitch# show running-config section interface Management1\ninterface Management1\n   ip address 10.252.36.194/25\u003c/pre\u003e"
            }
          ],
          "value": "switch# show running-config section router rip\nrouter rip\n   network 10.252.36.128/25\n   no shutdown\n\nswitch# show running-config section interface Management1\ninterface Management1\n   ip address 10.252.36.194/25"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "On affected Arista EOS platforms with Routing Information Protocol version 2 (RIPv2) configured, under certain conditions, RIPv2 might be silently enabled on management interfaces even when the RIP agent intends to disable it. It allows an unauthenticated attacker with access to the adjacent network to send crafted RIPv2 route advertisements to the device\u0027s management IP address. The device could accept and install those routes without authentication.\n\nSuccessful exploitation could allow the attacker to redirect traffic flows to an attacker-controlled destination, install more-specific routes that blackhole legitimate traffic, or otherwise disrupt network reachability for systems whose traffic passes through the affected device."
        }
      ],
      "impacts": [
        {
          "capecId": "CAPEC-212",
          "descriptions": [
            {
              "lang": "en",
              "value": "CAPEC-212 Functionality Misuse"
            }
          ]
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 9.6,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:H",
            "version": "3.1"
          }
        },
        {
          "cvssV4_0": {
            "baseScore": 6.1,
            "baseSeverity": "MEDIUM",
            "vectorString": "CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:H/SC:N/SI:L/SA:L",
            "version": "4.0"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-440",
              "description": "CWE-440 Expected Behavior Violation",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-11-10T20:10:00.035Z",
        "orgId": "c8b34d1a-69ae-45c3-88fe-f3b3d44f39b7",
        "shortName": "Arista"
      },
      "references": [
        {
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://www.arista.com/en/support/advisories-notices/security-advisory/25042-security-advisory-0220"
        }
      ],
      "source": {
        "advisory": "Security Advisory 0220",
        "defects": [
          "1981966"
        ],
        "discovery": "INTERNAL"
      },
      "title": "Security Advisory 0220",
      "workarounds": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "\u003cpre\u003eswitch# configure terminal\nswitch(config)# router rip\nswitch(config-router-rip)# shutdown\nswitch(config-router-rip)# end\n\n(Workaround: In environments where RIP is not required, disable it within each affected VRF instance. If RIP is necessary on data interfaces but not the management subnet, verify no RIP network prefix matches the management subnet.)\u003c/pre\u003e"
            }
          ],
          "value": "switch# configure terminal\nswitch(config)# router rip\nswitch(config-router-rip)# shutdown\nswitch(config-router-rip)# end\n\n(Workaround: In environments where RIP is not required, disable it within each affected VRF instance. If RIP is necessary on data interfaces but not the management subnet, verify no RIP network prefix matches the management subnet.)"
        }
      ]
    }
  },
  "cveMetadata": {
    "assignerOrgId": "c8b34d1a-69ae-45c3-88fe-f3b3d44f39b7",
    "assignerShortName": "Arista",
    "cveId": "CVE-2026-121367",
    "datePublished": "2026-11-10T20:10:00.035Z",
    "dateReserved": "2026-11-03T11:27:14.150Z",
    "dateUpdated": "2026-11-10T20:10:00.035Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-121367",
      "date": "2026-11-13",
      "epss": "0.00292",
      "percentile": "0.22055"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "defaultStatus": "unaffected",
                "platforms": [
                  "710 Series",
                  "720D Series",
                  "720XP/722XPM Series",
                  "750X Series",
                  "7010TX Series",
                  "7020R/R4 Series",
                  "7130 Series running EOS",
                  "7170 Series",
                  "7050X3/X4 Series",
                  "7060X/X2/X4/X5/X6/XE7 Series",
                  "7260X/X3 Series",
                  "7280R/R2/R3/R4 Series",
                  "7300X/X3 Series",
                  "7320X Series",
                  "7358X4 Series",
                  "7368X4 Series",
                  "7388X5 Series",
                  "7500R/R2/R3 Series",
                  "7800R3/R4 Series",
                  "7700R4 Series",
                  "AWE 5000 Series",
                  "AWE 7200R Series",
                  "ZTX-7200 Series",
                  "CloudEOS",
                  "cEOS-lab",
                  "vEOS-lab",
                  "CloudVision eXchange, virtual or physical appliance"
                ],
                "product": "EOS",
                "vendor": "Arista Networks",
                "versions": [
                  {
                    "lessThan": "4.33.0F",
                    "status": "affected",
                    "version": "1.0.0",
                    "versionType": "custom"
                  },
                  {
                    "lessThanOrEqual": "4.33.10M",
                    "status": "affected",
                    "version": "4.33.0F",
                    "versionType": "custom"
                  },
                  {
                    "lessThanOrEqual": "4.34.8M",
                    "status": "affected",
                    "version": "4.34.0F",
                    "versionType": "custom"
                  },
                  {
                    "lessThanOrEqual": "4.35.6M",
                    "status": "affected",
                    "version": "4.35.0F",
                    "versionType": "custom"
                  },
                  {
                    "lessThanOrEqual": "4.36.2F",
                    "status": "affected",
                    "version": "4.36.0F",
                    "versionType": "custom"
                  },
                  {
                    "status": "affected",
                    "version": "4.37.0F",
                    "versionType": "custom"
                  }
                ]
              }
            ],
            "source": "psirt@arista.com"
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "On affected Arista EOS platforms with Routing Information Protocol version 2 (RIPv2) configured, under certain conditions, RIPv2 might be silently enabled on management interfaces even when the RIP agent intends to disable it. It allows an unauthenticated attacker with access to the adjacent network to send crafted RIPv2 route advertisements to the device\u0027s management IP address. The device could accept and install those routes without authentication.\n\nSuccessful exploitation could allow the attacker to redirect traffic flows to an attacker-controlled destination, install more-specific routes that blackhole legitimate traffic, or otherwise disrupt network reachability for systems whose traffic passes through the affected device."
          }
        ],
        "id": "CVE-2026-121367",
        "lastModified": "2026-11-12T19:24:37.847",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "ADJACENT_NETWORK",
                "availabilityImpact": "HIGH",
                "baseScore": 9.6,
                "baseSeverity": "CRITICAL",
                "confidentialityImpact": "LOW",
                "integrityImpact": "HIGH",
                "privilegesRequired": "NONE",
                "scope": "CHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:H",
                "version": "3.1"
              },
              "exploitabilityScore": 2.8,
              "impactScore": 6.0,
              "source": "psirt@arista.com",
              "type": "Secondary"
            }
          ],
          "cvssMetricV40": [
            {
              "cvssData": {
                "Automatable": "NOT_DEFINED",
                "Recovery": "NOT_DEFINED",
                "Safety": "NOT_DEFINED",
                "attackComplexity": "LOW",
                "attackRequirements": "PRESENT",
                "attackVector": "ADJACENT",
                "availabilityRequirement": "NOT_DEFINED",
                "baseScore": 6.1,
                "baseSeverity": "MEDIUM",
                "confidentialityRequirement": "NOT_DEFINED",
                "exploitMaturity": "NOT_DEFINED",
                "integrityRequirement": "NOT_DEFINED",
                "modifiedAttackComplexity": "NOT_DEFINED",
                "modifiedAttackRequirements": "NOT_DEFINED",
                "modifiedAttackVector": "NOT_DEFINED",
                "modifiedPrivilegesRequired": "NOT_DEFINED",
                "modifiedSubAvailabilityImpact": "NOT_DEFINED",
                "modifiedSubConfidentialityImpact": "NOT_DEFINED",
                "modifiedSubIntegrityImpact": "NOT_DEFINED",
                "modifiedUserInteraction": "NOT_DEFINED",
                "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
                "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
                "modifiedVulnIntegrityImpact": "NOT_DEFINED",
                "privilegesRequired": "NONE",
                "providerUrgency": "NOT_DEFINED",
                "subAvailabilityImpact": "LOW",
                "subConfidentialityImpact": "NONE",
                "subIntegrityImpact": "LOW",
                "userInteraction": "NONE",
                "valueDensity": "NOT_DEFINED",
                "vectorString": "CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:L/VI:H/VA:H/SC:N/SI:L/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
                "version": "4.0",
                "vulnAvailabilityImpact": "HIGH",
                "vulnConfidentialityImpact": "LOW",
                "vulnIntegrityImpact": "HIGH",
                "vulnerabilityResponseEffort": "NOT_DEFINED"
              },
              "source": "psirt@arista.com",
              "type": "Secondary"
            }
          ]
        },
        "published": "2026-11-10T20:18:55.933",
        "references": [
          {
            "source": "psirt@arista.com",
            "url": "https://www.arista.com/en/support/advisories-notices/security-advisory/25042-security-advisory-0220"
          }
        ],
        "sourceIdentifier": "psirt@arista.com",
        "vulnStatus": "Awaiting Analysis",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-440"
              }
            ],
            "source": "psirt@arista.com",
            "type": "Secondary"
          }
        ]
      }
    }
  }
}



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