CVE-2021-21086
Acrobat Reader DC versions versions 2020.013.20074 (and earlier), 2020.001.30018 (and earlier) and 2017.011.30188 (and earlier) are affected by an Out-of-bounds Write vulnerability in the CoolType library. An unauthenticated attacker could leverage this vulnerability to achieve arbitrary code execution in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.
CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- Puntuación base: 7.8
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 4.71%
- Percentil entre todas las CVEs puntuadas: 92
- 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).
💥 Exploits públicos
Hay código de explotación o plantillas de detección públicos. No es lo mismo que explotación activa confirmada (KEV), pero aumenta el riesgo: parchee con prioridad.
- Prueba de concepto en GitHub (no verificada) · Lista de pruebas de concepto en GitHub
⚠️ Las pruebas de concepto de GitHub no están verificadas: algunas son falsas o contienen malware. No las ejecute nunca fuera de un laboratorio aislado.
Tecnologías afectadas (4)
CWE
- CWE-787
- CWE-787
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2021-21086",
"cveTags": [],
"metrics": {
"cvssMetricV2": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"version": "2.0",
"baseScore": 6.8,
"accessVector": "NETWORK",
"vectorString": "AV:N/AC:M/Au:N/C:P/I:P/A:P",
"authentication": "NONE",
"integrityImpact": "PARTIAL",
"accessComplexity": "MEDIUM",
"availabilityImpact": "PARTIAL",
"confidentialityImpact": "PARTIAL"
},
"acInsufInfo": false,
"impactScore": 6.4,
"baseSeverity": "MEDIUM",
"obtainAllPrivilege": false,
"exploitabilityScore": 8.6,
"obtainUserPrivilege": false,
"obtainOtherPrivilege": false,
"userInteractionRequired": true
}
],
"cvssMetricV31": [
{
"type": "Secondary",
"source": "psirt@adobe.com",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 7.8,
"attackVector": "LOCAL",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
"integrityImpact": "HIGH",
"userInteraction": "REQUIRED",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "NONE",
"confidentialityImpact": "HIGH"
},
"impactScore": 5.9,
"exploitabilityScore": 1.8
},
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 7.8,
"attackVector": "LOCAL",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H",
"integrityImpact": "HIGH",
"userInteraction": "REQUIRED",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "NONE",
"confidentialityImpact": "HIGH"
},
"impactScore": 5.9,
"exploitabilityScore": 1.8
}
]
},
"affected": [
{
"source": "psirt@adobe.com",
"affectedData": [
{
"vendor": "Adobe",
"product": "Acrobat Reader",
"versions": [
{
"status": "affected",
"version": "unspecified",
"versionType": "custom",
"lessThanOrEqual": "2020.013.20074"
},
{
"status": "affected",
"version": "unspecified",
"versionType": "custom",
"lessThanOrEqual": "2020.001.30018"
},
{
"status": "affected",
"version": "unspecified",
"versionType": "custom",
"lessThanOrEqual": "2017.011.30188"
},
{
"status": "affected",
"version": "unspecified",
"versionType": "custom",
"lessThanOrEqual": "None"
}
]
}
]
}
],
"published": "2021-09-02T16:15:07.457",
"references": [
{
"url": "https://helpx.adobe.com/security/products/acrobat/apsb21-09.html",
"tags": [
"Vendor Advisory"
],
"source": "psirt@adobe.com"
},
{
"url": "https://helpx.adobe.com/security/products/acrobat/apsb21-09.html",
"tags": [
"Vendor Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
}
],
"vulnStatus": "Modified",
"weaknesses": [
{
"type": "Secondary",
"source": "psirt@adobe.com",
"description": [
{
"lang": "en",
"value": "CWE-787"
}
]
},
{
"type": "Primary",
"source": "nvd@nist.gov",
"description": [
{
"lang": "en",
"value": "CWE-787"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "Acrobat Reader DC versions versions 2020.013.20074 (and earlier), 2020.001.30018 (and earlier) and 2017.011.30188 (and earlier) are affected by an Out-of-bounds Write vulnerability in the CoolType library. An unauthenticated attacker could leverage this vulnerability to achieve arbitrary code execution in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file."
},
{
"lang": "es",
"value": "Acrobat Reader DC versiones 2020.013.20074 (y anteriores), versiones 2020.001.30018 (y anteriores) y versiones 2017.011.30188 (y anteriores), están afectadas por una vulnerabilidad de escritura fuera de límites en la biblioteca CoolType. Un atacante no autenticado podría aprovechar esta vulnerabilidad para lograr una ejecución de código arbitrario en el contexto del usuario actual. Es requerida una interacción del usuario para explotar este problema, ya que la víctima debe abrir un archivo malicioso"
}
],
"lastModified": "2026-06-17T03:34:48.160",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:adobe:acrobat:*:*:*:*:classic:*:*:*",
"vulnerable": true,
"matchCriteriaId": "F8EE962C-2349-4E28-A16B-02402D22DCEE",
"versionEndIncluding": "17.011.30188",
"versionStartIncluding": "17.011.30056"
},
{
"criteria": "cpe:2.3:a:adobe:acrobat:*:*:*:*:classic:*:*:*",
"vulnerable": true,
"matchCriteriaId": "6AA3B8F3-7E2D-4463-AEC6-53AF49EB511F",
"versionEndIncluding": "20.001.30018",
"versionStartIncluding": "20.001.30005"
},
{
"criteria": "cpe:2.3:a:adobe:acrobat_dc:*:*:*:*:continuous:*:*:*",
"vulnerable": true,
"matchCriteriaId": "38F47320-0BA1-44AD-B2EB-2593E2E67169",
"versionEndIncluding": "20.013.20074",
"versionStartIncluding": "20.006.20042"
},
{
"criteria": "cpe:2.3:a:adobe:acrobat_reader:*:*:*:*:classic:*:*:*",
"vulnerable": true,
"matchCriteriaId": "E769E3AF-BCD8-4894-A5F3-7318DA56ABF1",
"versionEndIncluding": "17.011.30188",
"versionStartIncluding": "17.011.30059"
},
{
"criteria": "cpe:2.3:a:adobe:acrobat_reader:*:*:*:*:classic:*:*:*",
"vulnerable": true,
"matchCriteriaId": "D078D340-573A-40CD-A843-5875F4505632",
"versionEndIncluding": "20.001.300183",
"versionStartIncluding": "20.001.30005"
},
{
"criteria": "cpe:2.3:a:adobe:acrobat_reader_dc:*:*:*:*:continuous:*:*:*",
"vulnerable": true,
"matchCriteriaId": "AAE7CEAF-4CB3-4A17-821B-D69F0A4B69E1",
"versionEndIncluding": "20.013.20074",
"versionStartIncluding": "20.006.20042"
}
],
"operator": "OR"
},
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:o:apple:macos:-:*:*:*:*:*:*:*",
"vulnerable": false,
"matchCriteriaId": "387021A0-AF36-463C-A605-32EA7DAC172E"
},
{
"criteria": "cpe:2.3:o:microsoft:windows:-:*:*:*:*:*:*:*",
"vulnerable": false,
"matchCriteriaId": "A2572D17-1DE6-457B-99CC-64AFD54487EA"
}
],
"operator": "OR"
}
],
"operator": "AND"
}
],
"sourceIdentifier": "psirt@adobe.com"
}