CVE-2017-7820
Estado: ModificadaMedia (5.3)—
El operador "instanceof" puede omitir el mecanismo del wrapper Xray. Cuando se le llama en un contenido web desde el propio navegador o una extensión, el contenido web puede proporcionar su propio resultado para ese operador, pudiendo engañar al navegador o extensión para que manipule erróneamente el elemento. Esta vulnerabilidad afecta a las versiones anteriores a la 56 de Firefox.
CVSS
- Versión: 3.0
- Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
- Puntuación base: 5.3
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 1.19%
- Percentil entre todas las CVEs puntuadas: 67
- Fecha de la puntuación: 10/10/2026
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
- NVD-CWE-noinfo
Referencias
- http://www.securityfocus.com/bid/101057
- http://www.securitytracker.com/id/1039465
- https://bugzilla.mozilla.org/show_bug.cgi?id=1378207
- https://www.mozilla.org/security/advisories/mfsa2017-21/
- http://www.securityfocus.com/bid/101057
- http://www.securitytracker.com/id/1039465
- https://bugzilla.mozilla.org/show_bug.cgi?id=1378207
- https://www.mozilla.org/security/advisories/mfsa2017-21/
JSON original (NVD)
Mostrar
{
"id": "CVE-2017-7820",
"cveTags": [],
"metrics": {
"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
}
],
"cvssMetricV30": [
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"cvssData": {
"scope": "UNCHANGED",
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"vectorString": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/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": "security@mozilla.org",
"affectedData": [
{
"vendor": "Mozilla",
"product": "Firefox",
"versions": [
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"status": "affected",
"version": "unspecified",
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}
]
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]
}
],
"published": "2018-06-11T21:29:10.873",
"references": [
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"tags": [
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{
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"tags": [
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{
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"tags": [
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},
{
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"source": "af854a3a-2127-422b-91ae-364da2661108"
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],
"vulnStatus": "Modified",
"weaknesses": [
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"type": "Primary",
"source": "nvd@nist.gov",
"description": [
{
"lang": "en",
"value": "NVD-CWE-noinfo"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "The \"instanceof\" operator can bypass the Xray wrapper mechanism. When called on web content from the browser itself or an extension the web content can provide its own result for that operator, possibly tricking the browser or extension into mishandling the element. This vulnerability affects Firefox < 56."
},
{
"lang": "es",
"value": "El operador \"instanceof\" puede omitir el mecanismo del wrapper Xray. Cuando se le llama en un contenido web desde el propio navegador o una extensión, el contenido web puede proporcionar su propio resultado para ese operador, pudiendo engañar al navegador o extensión para que manipule erróneamente el elemento. Esta vulnerabilidad afecta a las versiones anteriores a la 56 de Firefox."
}
],
"lastModified": "2026-06-17T01:25:16.797",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
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"criteria": "cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*",
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"matchCriteriaId": "FEC7D85F-EE10-4144-B49D-DC88DE61352E",
"versionEndIncluding": "55.0.3"
}
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"operator": "OR"
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}
],
"sourceIdentifier": "security@mozilla.org"
}