CVE-2018-6918
Status: ModifiedHigh (7.5)—
In FreeBSD before 11.1-STABLE, 11.1-RELEASE-p9, 10.4-STABLE, 10.4-RELEASE-p8 and 10.3-RELEASE-p28, the length field of the ipsec option header does not count the size of the option header itself, causing an infinite loop when the length is zero. This issue can allow a remote attacker who is able to send an arbitrary packet to cause the machine to crash.
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: 4.21%
- Percentile among all scored CVEs: 91
- Score date: 10/7/2026
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
- http://seclists.org/fulldisclosure/2019/Jun/6
- http://www.securityfocus.com/bid/103666
- http://www.securitytracker.com/id/1040628
- https://seclists.org/bugtraq/2019/May/77
- https://security.FreeBSD.org/advisories/FreeBSD-SA-18:05.ipsec.asc
- https://support.apple.com/kb/HT210090
- https://support.apple.com/kb/HT210091
- http://seclists.org/fulldisclosure/2019/Jun/6
- http://www.securityfocus.com/bid/103666
- http://www.securitytracker.com/id/1040628
- https://seclists.org/bugtraq/2019/May/77
- https://security.FreeBSD.org/advisories/FreeBSD-SA-18:05.ipsec.asc
- https://support.apple.com/kb/HT210090
- https://support.apple.com/kb/HT210091
Raw JSON (NVD)
Show
{
"id": "CVE-2018-6918",
"cveTags": [],
"metrics": {
"cvssMetricV2": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"version": "2.0",
"baseScore": 7.8,
"accessVector": "NETWORK",
"vectorString": "AV:N/AC:L/Au:N/C:N/I:N/A:C",
"authentication": "NONE",
"integrityImpact": "NONE",
"accessComplexity": "LOW",
"availabilityImpact": "COMPLETE",
"confidentialityImpact": "NONE"
},
"acInsufInfo": false,
"impactScore": 6.9,
"baseSeverity": "HIGH",
"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": "secteam@freebsd.org",
"affectedData": [
{
"vendor": "FreeBSD",
"product": "FreeBSD",
"versions": [
{
"status": "affected",
"version": "All supported versions of FreeBSD."
}
]
}
]
}
],
"published": "2018-04-04T14:29:00.293",
"references": [
{
"url": "http://seclists.org/fulldisclosure/2019/Jun/6",
"source": "secteam@freebsd.org"
},
{
"url": "http://www.securityfocus.com/bid/103666",
"tags": [
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"VDB Entry"
],
"source": "secteam@freebsd.org"
},
{
"url": "http://www.securitytracker.com/id/1040628",
"tags": [
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],
"source": "secteam@freebsd.org"
},
{
"url": "https://seclists.org/bugtraq/2019/May/77",
"source": "secteam@freebsd.org"
},
{
"url": "https://security.FreeBSD.org/advisories/FreeBSD-SA-18:05.ipsec.asc",
"tags": [
"Vendor Advisory"
],
"source": "secteam@freebsd.org"
},
{
"url": "https://support.apple.com/kb/HT210090",
"source": "secteam@freebsd.org"
},
{
"url": "https://support.apple.com/kb/HT210091",
"source": "secteam@freebsd.org"
},
{
"url": "http://seclists.org/fulldisclosure/2019/Jun/6",
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "http://www.securityfocus.com/bid/103666",
"tags": [
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"source": "af854a3a-2127-422b-91ae-364da2661108"
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{
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"tags": [
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],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://seclists.org/bugtraq/2019/May/77",
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://security.FreeBSD.org/advisories/FreeBSD-SA-18:05.ipsec.asc",
"tags": [
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],
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://support.apple.com/kb/HT210090",
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://support.apple.com/kb/HT210091",
"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": "In FreeBSD before 11.1-STABLE, 11.1-RELEASE-p9, 10.4-STABLE, 10.4-RELEASE-p8 and 10.3-RELEASE-p28, the length field of the ipsec option header does not count the size of the option header itself, causing an infinite loop when the length is zero. This issue can allow a remote attacker who is able to send an arbitrary packet to cause the machine to crash."
},
{
"lang": "es",
"value": "En FreeBSD, en versiones anteriores a 11.1-STABLE, 11.1-RELEASE-p9, 10.4-STABLE, 10.4-RELEASE-p8 y 10.3-RELEASE-p28, el campo length de la cabecera de opción ipsec no cuenta el tamaño de la propia cabecera de opción. Esto provoca un bucle infinito cuando la longitud es cero. Este problema puede permitir que un atacante remoto que pueda enviar un paquete arbitrario haga que la máquina se cierre inesperadamente."
}
],
"lastModified": "2026-06-17T02:02:27.647",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:o:freebsd:freebsd:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "E766E867-C66B-4EAD-8A14-C6D194544438",
"versionEndExcluding": "10.4",
"versionStartIncluding": "10.0"
},
{
"criteria": "cpe:2.3:o:freebsd:freebsd:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "702C5136-33B6-4F0F-8FF7-C2BE3668DE70",
"versionEndExcluding": "11.1",
"versionStartIncluding": "11.0"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "secteam@freebsd.org"
}