CVE-2018-20578
Status: ModifiedHigh (7.5)—
An issue was discovered in NuttX before 7.27. The function netlib_parsehttpurl() in apps/netutils/netlib/netlib_parsehttpurl.c mishandles URLs longer than hostlen bytes (in the webclient, this is set by default to 40), leading to an Infinite Loop. The attack vector is the Location header of an HTTP 3xx response.
CVSS
- Version: 3.0
- Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Base score: 7.5
Exploitation probability (EPSS)
- Probability of exploitation in the next 30 days: 1.60%
- Percentile among all scored CVEs: 75
- Score date: 10/3/2026
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-835
References
Raw JSON (NVD)
Show
{
"id": "CVE-2018-20578",
"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:N/A:P",
"authentication": "NONE",
"integrityImpact": "NONE",
"accessComplexity": "LOW",
"availabilityImpact": "PARTIAL",
"confidentialityImpact": "NONE"
},
"acInsufInfo": false,
"impactScore": 2.9,
"baseSeverity": "MEDIUM",
"obtainAllPrivilege": false,
"exploitabilityScore": 10,
"obtainUserPrivilege": false,
"obtainOtherPrivilege": false,
"userInteractionRequired": false
}
],
"cvssMetricV30": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.0",
"baseScore": 7.5,
"attackVector": "NETWORK",
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"integrityImpact": "NONE",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "NONE",
"confidentialityImpact": "NONE"
},
"impactScore": 3.6,
"exploitabilityScore": 3.9
}
]
},
"affected": [
{
"source": "cve@mitre.org",
"affectedData": [
{
"vendor": "n/a",
"product": "n/a",
"versions": [
{
"status": "affected",
"version": "n/a"
}
]
}
]
}
],
"published": "2018-12-28T18:29:00.253",
"references": [
{
"url": "https://bitbucket.org/nuttx/nuttx/downloads/nuttx-7_27-README.txt",
"tags": [
"Release Notes",
"Third Party Advisory"
],
"source": "cve@mitre.org"
},
{
"url": "https://bitbucket.org/nuttx/nuttx/issues/119/denial-of-service-infinite-loop-while",
"tags": [
"Exploit",
"Patch",
"Third Party Advisory"
],
"source": "cve@mitre.org"
},
{
"url": "https://bitbucket.org/nuttx/nuttx/downloads/nuttx-7_27-README.txt",
"tags": [
"Release Notes",
"Third Party Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://bitbucket.org/nuttx/nuttx/issues/119/denial-of-service-infinite-loop-while",
"tags": [
"Exploit",
"Patch",
"Third Party Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
}
],
"vulnStatus": "Modified",
"weaknesses": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"description": [
{
"lang": "en",
"value": "CWE-835"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "An issue was discovered in NuttX before 7.27. The function netlib_parsehttpurl() in apps/netutils/netlib/netlib_parsehttpurl.c mishandles URLs longer than hostlen bytes (in the webclient, this is set by default to 40), leading to an Infinite Loop. The attack vector is the Location header of an HTTP 3xx response."
},
{
"lang": "es",
"value": "Se ha descubierto un problema en versiones anteriores a la 7.27 de NuttX. La función netlib_parsehttpurl() en apps/netutils/netlib/netlib_parsehttpurl.c gestiona de manera incorrecta las URL más largas que los bytes de hostlen (en el cliente web, esto se establece por defecto en 40), conduciendo a un bucle infinito. El vector de ataque es la cabecera Location de una respuesta HTTP 3xx."
}
],
"lastModified": "2026-06-17T01:53:07.313",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:nuttx:nuttx:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "18635B34-6239-44E0-9A24-CB288BA405E0",
"versionEndExcluding": "7.27"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "cve@mitre.org"
}