CVE-2021-34696
Estado: ModificadaMedia (5.8)—
A vulnerability in the access control list (ACL) programming of Cisco ASR 900 and ASR 920 Series Aggregation Services Routers could allow an unauthenticated, remote attacker to bypass a configured ACL. This vulnerability is due to incorrect programming of hardware when an ACL is configured using a method other than the configuration CLI. An attacker could exploit this vulnerability by attempting to send traffic through an affected device. A successful exploit could allow the attacker to bypass an ACL on the affected device.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
- Puntuación base: 5.8
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 1.00%
- Percentil entre todas las CVEs puntuadas: 62
- Fecha de la puntuación: 7/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
Tecnologías afectadas (1)
CWE
- CWE-284
- NVD-CWE-Other
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2021-34696",
"cveTags": [],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"id": "CVE-2021-34696",
"role": "CISA Coordinator",
"options": [
{
"exploitation": "none"
},
{
"automatable": "yes"
},
{
"technicalImpact": "partial"
}
],
"version": "2.0.3",
"timestamp": "2024-11-07T21:54:16.191005Z"
}
}
],
"cvssMetricV2": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"version": "2.0",
"baseScore": 5,
"accessVector": "NETWORK",
"vectorString": "AV:N/AC:L/Au:N/C:N/I:P/A:N",
"authentication": "NONE",
"integrityImpact": "PARTIAL",
"accessComplexity": "LOW",
"availabilityImpact": "NONE",
"confidentialityImpact": "NONE"
},
"acInsufInfo": false,
"impactScore": 2.9,
"baseSeverity": "MEDIUM",
"obtainAllPrivilege": false,
"exploitabilityScore": 10,
"obtainUserPrivilege": false,
"obtainOtherPrivilege": false,
"userInteractionRequired": false
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "psirt@cisco.com",
"cvssData": {
"scope": "CHANGED",
"version": "3.1",
"baseScore": 5.8,
"attackVector": "NETWORK",
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N",
"integrityImpact": "LOW",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "NONE",
"privilegesRequired": "NONE",
"confidentialityImpact": "NONE"
},
"impactScore": 1.4,
"exploitabilityScore": 3.9
},
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"scope": "CHANGED",
"version": "3.1",
"baseScore": 5.8,
"attackVector": "NETWORK",
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N",
"integrityImpact": "LOW",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "NONE",
"privilegesRequired": "NONE",
"confidentialityImpact": "NONE"
},
"impactScore": 1.4,
"exploitabilityScore": 3.9
}
]
},
"affected": [
{
"source": "psirt@cisco.com",
"affectedData": [
{
"vendor": "Cisco",
"product": "Cisco IOS XE Software",
"versions": [
{
"status": "affected",
"version": "n/a"
}
]
}
]
}
],
"published": "2021-09-23T03:15:15.633",
"references": [
{
"url": "https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asr900acl-UeEyCxkv",
"tags": [
"Vendor Advisory"
],
"source": "psirt@cisco.com"
},
{
"url": "https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asr900acl-UeEyCxkv",
"tags": [
"Vendor Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
}
],
"vulnStatus": "Modified",
"weaknesses": [
{
"type": "Secondary",
"source": "psirt@cisco.com",
"description": [
{
"lang": "en",
"value": "CWE-284"
}
]
},
{
"type": "Primary",
"source": "nvd@nist.gov",
"description": [
{
"lang": "en",
"value": "NVD-CWE-Other"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "A vulnerability in the access control list (ACL) programming of Cisco ASR 900 and ASR 920 Series Aggregation Services Routers could allow an unauthenticated, remote attacker to bypass a configured ACL. This vulnerability is due to incorrect programming of hardware when an ACL is configured using a method other than the configuration CLI. An attacker could exploit this vulnerability by attempting to send traffic through an affected device. A successful exploit could allow the attacker to bypass an ACL on the affected device."
},
{
"lang": "es",
"value": "Una vulnerabilidad en la programación de la lista de control de acceso (ACL) de Cisco ASR 900 and ASR 920 Series Aggregation Services Routers podría permitir a un atacante remoto no autenticado omitir una ACL configurada. Esta vulnerabilidad es debido a la programación incorrecta del hardware cuando se configura una ACL mediante un método distinto de la CLI de configuración. Un atacante podría explotar esta vulnerabilidad al intentar enviar tráfico mediante un dispositivo afectado. Una explotación con éxito podría permitir al atacante omitir una ACL en el dispositivo afectado"
}
],
"lastModified": "2026-06-17T03:56:22.137",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:o:cisco:ios_xe:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "63658947-333C-4689-A50C-9EA874B8FB4A",
"versionEndIncluding": "17.3.2"
}
],
"operator": "OR"
},
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:h:cisco:asr_902:-:*:*:*:*:*:*:*",
"vulnerable": false,
"matchCriteriaId": "70352B04-C3FD-47F5-A2F8-691CF63EB50D"
},
{
"criteria": "cpe:2.3:h:cisco:asr_903:-:*:*:*:*:*:*:*",
"vulnerable": false,
"matchCriteriaId": "51938C0A-AFDB-4B12-BB64-9C67FC0C738F"
},
{
"criteria": "cpe:2.3:h:cisco:asr_907:-:*:*:*:*:*:*:*",
"vulnerable": false,
"matchCriteriaId": "A18E4A46-10D3-48F8-9E92-377ACA447257"
},
{
"criteria": "cpe:2.3:h:cisco:asr_920-10sz-pd:-:*:*:*:*:*:*:*",
"vulnerable": false,
"matchCriteriaId": "DBE110B5-CC6E-4103-9983-4195BCC28165"
},
{
"criteria": "cpe:2.3:h:cisco:asr_920-10sz-pd_r:-:*:*:*:*:*:*:*",
"vulnerable": false,
"matchCriteriaId": "B97DDC45-ABD1-4C8F-A249-0865345637A4"
},
{
"criteria": "cpe:2.3:h:cisco:asr_920-12cz-a:-:*:*:*:*:*:*:*",
"vulnerable": false,
"matchCriteriaId": "3FE4D129-435B-45DD-838D-4017BD94DF93"
},
{
"criteria": "cpe:2.3:h:cisco:asr_920-12cz-a_r:-:*:*:*:*:*:*:*",
"vulnerable": false,
"matchCriteriaId": "456C68A8-F3C8-4302-B55A-134979B42045"
},
{
"criteria": "cpe:2.3:h:cisco:asr_920-12cz-d:-:*:*:*:*:*:*:*",
"vulnerable": false,
"matchCriteriaId": "870D5B63-A1D5-442A-B2B9-9E522E5DB08F"
},
{
"criteria": "cpe:2.3:h:cisco:asr_920-12cz-d_r:-:*:*:*:*:*:*:*",
"vulnerable": false,
"matchCriteriaId": "17C6733C-F77B-4688-B051-C1557F4D8D41"
},
{
"criteria": "cpe:2.3:h:cisco:asr_920-12sz-im:-:*:*:*:*:*:*:*",
"vulnerable": false,
"matchCriteriaId": "2BD45D77-4097-4AFB-98DF-5B8188316C20"
},
{
"criteria": "cpe:2.3:h:cisco:asr_920-12sz-im_r:-:*:*:*:*:*:*:*",
"vulnerable": false,
"matchCriteriaId": "489F97AB-5C6D-4AFE-BE5A-ABF7F9ED8B66"
},
{
"criteria": "cpe:2.3:h:cisco:asr_920-24sz-im:-:*:*:*:*:*:*:*",
"vulnerable": false,
"matchCriteriaId": "064DB97B-9E52-45BC-9F43-8FCB5570FC7D"
},
{
"criteria": "cpe:2.3:h:cisco:asr_920-24sz-im_r:-:*:*:*:*:*:*:*",
"vulnerable": false,
"matchCriteriaId": "31608C12-FBED-4EAD-96EC-48BC4B356B77"
},
{
"criteria": "cpe:2.3:h:cisco:asr_920-24sz-m:-:*:*:*:*:*:*:*",
"vulnerable": false,
"matchCriteriaId": "D989205A-0576-415C-935E-E83AD42FD1CB"
},
{
"criteria": "cpe:2.3:h:cisco:asr_920-24sz-m_r:-:*:*:*:*:*:*:*",
"vulnerable": false,
"matchCriteriaId": "6D21D9A5-DE8F-4C55-B03F-35C04C270A40"
},
{
"criteria": "cpe:2.3:h:cisco:asr_920-24tz-m:-:*:*:*:*:*:*:*",
"vulnerable": false,
"matchCriteriaId": "78C3EB40-574A-48F7-A679-90F62ED976B5"
},
{
"criteria": "cpe:2.3:h:cisco:asr_920-24tz-m_r:-:*:*:*:*:*:*:*",
"vulnerable": false,
"matchCriteriaId": "B6CC6206-DF19-4636-84C2-8912E443D122"
},
{
"criteria": "cpe:2.3:h:cisco:asr_920-4sz-a:-:*:*:*:*:*:*:*",
"vulnerable": false,
"matchCriteriaId": "85489F69-EAF0-4971-8C93-36838A8AA00E"
},
{
"criteria": "cpe:2.3:h:cisco:asr_920-4sz-a_r:-:*:*:*:*:*:*:*",
"vulnerable": false,
"matchCriteriaId": "BE95FEC1-12F3-44FC-B922-CD18CADB42FE"
},
{
"criteria": "cpe:2.3:h:cisco:asr_920-4sz-d:-:*:*:*:*:*:*:*",
"vulnerable": false,
"matchCriteriaId": "2D029B0C-2DAE-491A-90B4-79C093EC9E48"
},
{
"criteria": "cpe:2.3:h:cisco:asr_920-4sz-d_r:-:*:*:*:*:*:*:*",
"vulnerable": false,
"matchCriteriaId": "BE37BC85-7758-4412-A5E6-0F1A19E8776B"
},
{
"criteria": "cpe:2.3:h:cisco:asr_920u-12sz-im:-:*:*:*:*:*:*:*",
"vulnerable": false,
"matchCriteriaId": "BA179D79-07E7-4721-85BB-0C740B516B1F"
}
],
"operator": "OR"
}
],
"operator": "AND"
}
],
"sourceIdentifier": "psirt@cisco.com"
}