CVE-2019-1918

A vulnerability in the implementation of Intermediate System–to–Intermediate System (IS–IS) routing protocol functionality in Cisco IOS XR Software could allow an unauthenticated attacker who is in the same IS-IS area to cause a denial of service (DoS) condition. The vulnerability is due to incorrect processing of IS–IS link-state protocol data units (PDUs). An attacker could exploit this vulnerability by sending specific link-state PDUs to an affected system to be processed. A successful exploit could allow the attacker to cause incorrect calculations used in the weighted remote shared risk link groups (SRLG) or in the IGP Flexible Algorithm. It could also cause tracebacks to the logs or potentially cause the receiving device to crash the IS–IS process, resulting in a DoS condition.

CVSS v3 7.4 HIGH
CVSS v2.0 6.1 MEDIUM

7.4^/10

CVSS v3 : HIGH

Vector :

Exploitability : 2.8 / Impact : 4.0

Attack Vector ADJACENT_NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope CHANGED

6.1^/10

CVSS v2.0 : MEDIUM

Vector : AV:A/AC:L/Au:N/C:N/I:N/A:C

Exploitability : 6.5 / Impact : 6.9

Access Vector ADJACENT_NETWORK

Access Complexity LOW

Authentication NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact COMPLETE

References

Link	Resource
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190807-iosxr-isis-dos-1918	Vendor Advisory

Configurations

Configuration 1 (hide)

cpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*

Configuration 2 (hide)

OR	cpe:2.3:o:cisco:carrier_routing_system:6.5.1:::::::*
	cpe:2.3:o:cisco:carrier_routing_system:6.5.3:::::::*

History

No history.

Information

Published : 2019-08-07 22:15

Updated : 2023-12-10 12:59

NVD link : CVE-2019-1918

Mitre link : CVE-2019-1918

CVE.ORG link : CVE-2019-1918

JSON object : View

Products Affected

cisco

carrier_routing_system
ios_xr

CWE

CWE-682

Incorrect Calculation

CWE-20

Improper Input Validation

{"id": "CVE-2019-1918", "metrics": {"cvssMetricV2": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"version": "2.0", "baseScore": 6.1, "accessVector": "ADJACENT_NETWORK", "vectorString": "AV:A/AC:L/Au:N/C:N/I:N/A:C", "authentication": "NONE", "integrityImpact": "NONE", "accessComplexity": "LOW", "availabilityImpact": "COMPLETE", "confidentialityImpact": "NONE"}, "acInsufInfo": false, "impactScore": 6.9, "baseSeverity": "MEDIUM", "obtainAllPrivilege": false, "exploitabilityScore": 6.5, "obtainUserPrivilege": false, "obtainOtherPrivilege": false, "userInteractionRequired": false}], "cvssMetricV30": [{"type": "Secondary", "source": "ykramarz@cisco.com", "cvssData": {"scope": "CHANGED", "version": "3.0", "baseScore": 7.4, "attackVector": "ADJACENT_NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 4.0, "exploitabilityScore": 2.8}], "cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "CHANGED", "version": "3.1", "baseScore": 7.4, "attackVector": "ADJACENT_NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 4.0, "exploitabilityScore": 2.8}]}, "published": "2019-08-07T22:15:15.447", "references": [{"url": "https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190807-iosxr-isis-dos-1918", "tags": ["Vendor Advisory"], "source": "ykramarz@cisco.com"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "CWE-682"}]}, {"type": "Secondary", "source": "ykramarz@cisco.com", "description": [{"lang": "en", "value": "CWE-20"}]}], "descriptions": [{"lang": "en", "value": "A vulnerability in the implementation of Intermediate System–to–Intermediate System (IS–IS) routing protocol functionality in Cisco IOS XR Software could allow an unauthenticated attacker who is in the same IS-IS area to cause a denial of service (DoS) condition. The vulnerability is due to incorrect processing of IS–IS link-state protocol data units (PDUs). An attacker could exploit this vulnerability by sending specific link-state PDUs to an affected system to be processed. A successful exploit could allow the attacker to cause incorrect calculations used in the weighted remote shared risk link groups (SRLG) or in the IGP Flexible Algorithm. It could also cause tracebacks to the logs or potentially cause the receiving device to crash the IS–IS process, resulting in a DoS condition."}, {"lang": "es", "value": "Una vulnerabilidad en la implementaci\u00f3n en la funcionalidad del protocolo de enrutamiento de Intermediate System\u2013to\u2013Intermediate System (IS\u2013IS) en el software IOS XR de Cisco, podr\u00eda permitir a un atacante no autenticado que se encuentre en la misma \u00e1rea de IS-IS causar una condici\u00f3n de denegaci\u00f3n de servicio (DoS). La vulnerabilidad es debido al procesamiento incorrecto de las unidades de datos del protocolo (PDU) de estado de enlace de IS\u2013IS. Un atacante podr\u00eda explotar esta vulnerabilidad enviando PDU espec\u00edficas de estado de enlace a un sistema afectado para su procesamiento. Una explotaci\u00f3n con \u00e9xito podr\u00eda permitir al atacante causar c\u00e1lculos incorrectos utilizados en los grupos de enlace de riesgo compartido remoto ponderado (SRLG) o en el Algoritmo Flexible IGP. Tambi\u00e9n podr\u00eda causar trazas de vuelta en los registros o potencialmente causar que el dispositivo receptor bloquee el proceso IS\u2013IS, resultando en una condici\u00f3n DoS."}], "lastModified": "2020-10-16T14:36:36.990", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:cisco:ios_xr:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "84AF0440-E249-4656-B4E4-C62C58DA8BB9", "versionEndExcluding": "6.6.3", "versionStartIncluding": "6.5.2"}], "operator": "OR"}]}, {"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:cisco:carrier_routing_system:6.5.1:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "CFF40626-3D2C-42F2-A4B5-947118099FF4"}, {"criteria": "cpe:2.3:o:cisco:carrier_routing_system:6.5.3:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "CE3F3615-A41D-4C14-BBFC-343AEEFECBDF"}], "operator": "OR"}]}], "sourceIdentifier": "ykramarz@cisco.com"}