CVE-2020-15667
Status: ModifiedHigh (8.8)—
When processing a MAR update file, after the signature has been validated, an invalid name length could result in a heap overflow, leading to memory corruption and potentially arbitrary code execution. Within Firefox as released by Mozilla, this issue is only exploitable with the Mozilla-controlled signing key. This vulnerability affects Firefox < 80.
CVSS
- Version: 3.1
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- Base score: 8.8
Exploitation probability (EPSS)
- Probability of exploitation in the next 30 days: 1.65%
- Percentile among all scored CVEs: 76
- Score date: 10/9/2026
EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).
Affected technologies (1)
CWEs
- CWE-787
References
Raw JSON (NVD)
Show
{
"id": "CVE-2020-15667",
"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": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 8.8,
"attackVector": "NETWORK",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:N/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": 2.8
}
]
},
"affected": [
{
"source": "security@mozilla.org",
"affectedData": [
{
"vendor": "Mozilla",
"product": "Firefox",
"versions": [
{
"status": "affected",
"version": "unspecified",
"lessThan": "80",
"versionType": "custom"
}
]
}
]
}
],
"published": "2020-10-01T19:15:13.267",
"references": [
{
"url": "https://bugzilla.mozilla.org/show_bug.cgi?id=1653371",
"tags": [
"Issue Tracking",
"Permissions Required",
"Vendor Advisory"
],
"source": "security@mozilla.org"
},
{
"url": "https://www.mozilla.org/security/advisories/mfsa2020-36/",
"tags": [
"Release Notes",
"Vendor Advisory"
],
"source": "security@mozilla.org"
},
{
"url": "https://bugzilla.mozilla.org/show_bug.cgi?id=1653371",
"tags": [
"Issue Tracking",
"Permissions Required",
"Vendor Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://www.mozilla.org/security/advisories/mfsa2020-36/",
"tags": [
"Release Notes",
"Vendor Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
}
],
"vulnStatus": "Modified",
"weaknesses": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"description": [
{
"lang": "en",
"value": "CWE-787"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "When processing a MAR update file, after the signature has been validated, an invalid name length could result in a heap overflow, leading to memory corruption and potentially arbitrary code execution. Within Firefox as released by Mozilla, this issue is only exploitable with the Mozilla-controlled signing key. This vulnerability affects Firefox < 80."
},
{
"lang": "es",
"value": "Cuando se procesa un archivo de actualización MAR, después de que haya sido comprobada la firma, una longitud de nombre no válida podría resultar en un desbordamiento de la pila, conllevando a una corrupción de la memoria y una ejecución de código potencialmente arbitraria. En Firefox, tal como es lanzado por Mozilla, este problema solo es explotable con la clave de firma controlada por Mozilla. Esta vulnerabilidad afecta a Firefox versiones anteriores a 80"
}
],
"lastModified": "2026-06-17T02:57:01.057",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "334D3118-529D-4AAB-82A4-1EC3AA047D3D",
"versionEndExcluding": "80.0"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "security@mozilla.org"
}