CVE-2016-6439
Status: ModifiedHigh (7.5)—
A vulnerability in the detection engine reassembly of HTTP packets for Cisco Firepower System Software before 6.0.1 could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition due to the Snort process unexpectedly restarting. The vulnerability is due to improper handling of an HTTP packet stream. An attacker could exploit this vulnerability by sending a crafted HTTP packet stream to the detection engine on the targeted device. An exploit could allow the attacker to cause a DoS condition if the Snort process restarts and traffic inspection is bypassed or traffic is dropped.
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: 1.63%
- Percentile among all scored CVEs: 76
- 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-399
References
- http://www.securityfocus.com/bid/93787
- http://www.securitytracker.com/id/1037061
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20161019-fpsnort
- http://www.securityfocus.com/bid/93787
- http://www.securitytracker.com/id/1037061
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20161019-fpsnort
Raw JSON (NVD)
Show
{
"id": "CVE-2016-6439",
"cveTags": [],
"metrics": {
"cvssMetricV2": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"version": "2.0",
"baseScore": 4.3,
"accessVector": "NETWORK",
"vectorString": "AV:N/AC:M/Au:N/C:N/I:N/A:P",
"authentication": "NONE",
"integrityImpact": "NONE",
"accessComplexity": "MEDIUM",
"availabilityImpact": "PARTIAL",
"confidentialityImpact": "NONE"
},
"acInsufInfo": false,
"impactScore": 2.9,
"baseSeverity": "MEDIUM",
"obtainAllPrivilege": false,
"exploitabilityScore": 8.6,
"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": "psirt@cisco.com",
"affectedData": [
{
"vendor": "n/a",
"product": "Cisco Firepower System Software before 6.0.1",
"versions": [
{
"status": "affected",
"version": "Cisco Firepower System Software before 6.0.1"
}
]
}
]
}
],
"published": "2016-10-27T21:59:11.093",
"references": [
{
"url": "http://www.securityfocus.com/bid/93787",
"source": "psirt@cisco.com"
},
{
"url": "http://www.securitytracker.com/id/1037061",
"source": "psirt@cisco.com"
},
{
"url": "https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20161019-fpsnort",
"tags": [
"Vendor Advisory"
],
"source": "psirt@cisco.com"
},
{
"url": "http://www.securityfocus.com/bid/93787",
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "http://www.securitytracker.com/id/1037061",
"source": "af854a3a-2127-422b-91ae-364da2661108"
},
{
"url": "https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20161019-fpsnort",
"tags": [
"Vendor Advisory"
],
"source": "af854a3a-2127-422b-91ae-364da2661108"
}
],
"vulnStatus": "Modified",
"weaknesses": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"description": [
{
"lang": "en",
"value": "CWE-399"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "A vulnerability in the detection engine reassembly of HTTP packets for Cisco Firepower System Software before 6.0.1 could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition due to the Snort process unexpectedly restarting. The vulnerability is due to improper handling of an HTTP packet stream. An attacker could exploit this vulnerability by sending a crafted HTTP packet stream to the detection engine on the targeted device. An exploit could allow the attacker to cause a DoS condition if the Snort process restarts and traffic inspection is bypassed or traffic is dropped."
},
{
"lang": "es",
"value": "Una vulnerabilidad en el reensamblaje del motor de detección de paquetes HTTP para Cisco Firepower System Software en versiones anteriores a 6.0.1 podría permitir a un atacante remoto no autenticado provocar una condición de denegación de servicio (DoS) debido al reinicio inesperado del proceso Snort. La vulnerabilidad se debe al manejo incorrecto de un flujo de paquetes HTTP. Un atacante puede explotar esta vulnerabilidad mandado un flujo de paquetes HTTP manipulados al motor de detección en el dispositivo objetivo. Una explotación puede permitir al atacante provocar una condición DoS si el proceso Snort se reinicia y la inspección del tráfico se elude o el tráfico se cae."
}
],
"lastModified": "2026-06-17T00:51:02.047",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:a:cisco:secure_firewall_management_center:5.3.0:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "30E233C0-7547-479D-BC2B-A9F75106ADF5"
},
{
"criteria": "cpe:2.3:a:cisco:secure_firewall_management_center:5.3.0.2:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "6208D84A-C7EE-4F9D-82B2-C3BD657A6B3A"
},
{
"criteria": "cpe:2.3:a:cisco:secure_firewall_management_center:5.3.0.3:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "E12A7E1A-DD5F-4D24-B40C-9B6A4B06B7E6"
},
{
"criteria": "cpe:2.3:a:cisco:secure_firewall_management_center:5.3.0.4:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "E80F6ABE-ED3A-4F37-91E7-102DB4B63BC4"
},
{
"criteria": "cpe:2.3:a:cisco:secure_firewall_management_center:5.3.1:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "9FC04411-7DDF-4E11-A22C-1013396AC47B"
},
{
"criteria": "cpe:2.3:a:cisco:secure_firewall_management_center:5.3.1.3:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "B03AFE63-7D90-4092-9AB0-E05531EB0412"
},
{
"criteria": "cpe:2.3:a:cisco:secure_firewall_management_center:5.3.1.4:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "C06AC416-34EE-4881-8CCE-7E5CDD185364"
},
{
"criteria": "cpe:2.3:a:cisco:secure_firewall_management_center:5.3.1.5:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "47D22E4A-D02B-48E7-86D9-2A05A07C8A54"
},
{
"criteria": "cpe:2.3:a:cisco:secure_firewall_management_center:5.3.1.6:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "8695C71C-53B3-49F6-9BDD-85A45762D9D6"
},
{
"criteria": "cpe:2.3:a:cisco:secure_firewall_management_center:5.4.0:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "27EA38C1-A34F-430A-92F7-1D299F78B449"
},
{
"criteria": "cpe:2.3:a:cisco:secure_firewall_management_center:5.4.0.2:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "DE5CF68A-AAF1-4103-AD83-E2192785B31B"
},
{
"criteria": "cpe:2.3:a:cisco:secure_firewall_management_center:5.4.1:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "38ACE806-3514-4D95-85DA-BAD7245011A0"
},
{
"criteria": "cpe:2.3:a:cisco:secure_firewall_management_center:5.4.1.1:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "1898CADB-3B2B-4A3E-86DD-23A9E1A3E40F"
},
{
"criteria": "cpe:2.3:a:cisco:secure_firewall_management_center:5.4.1.2:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "8D6B5ED0-0E42-45A2-BBBB-148C2BE5DD14"
},
{
"criteria": "cpe:2.3:a:cisco:secure_firewall_management_center:5.4.1.3:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "0091657B-E242-4664-8F2F-85B8FCDF3EE8"
},
{
"criteria": "cpe:2.3:a:cisco:secure_firewall_management_center:5.4.1.4:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "95D7DA95-E977-4D06-92C8-E4E8B464E1D2"
},
{
"criteria": "cpe:2.3:a:cisco:secure_firewall_management_center:5.4.1.5:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "15B5C864-D82A-43BB-B193-CB9756A3B8BC"
},
{
"criteria": "cpe:2.3:a:cisco:secure_firewall_management_center:5.4.1.6:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "AA8E3657-BC3D-4A7D-8523-0D64F69CFE8E"
},
{
"criteria": "cpe:2.3:a:cisco:secure_firewall_management_center:5.4_base:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "9B2E1AA9-8A80-489A-8A6F-E9034E7D2A82"
},
{
"criteria": "cpe:2.3:a:cisco:secure_firewall_management_center:6.0.0:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "036E4035-E8E2-4964-A6F4-7292E1804E91"
},
{
"criteria": "cpe:2.3:a:cisco:secure_firewall_management_center:6.0.0.0:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "AF40DB44-C213-466E-B473-B07B30A42B34"
},
{
"criteria": "cpe:2.3:a:cisco:secure_firewall_management_center:6.0.0.1:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "B6FD6283-CC58-4864-AA24-F6C6DDE630FC"
},
{
"criteria": "cpe:2.3:a:cisco:secure_firewall_management_center:6.0.1:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "6D1AFAC1-419D-4ADB-868B-1544BED58B7F"
},
{
"criteria": "cpe:2.3:a:cisco:secure_firewall_management_center:6.0_base:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "554F229F-A0F5-4CA9-9778-5585E01ADF6E"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "psirt@cisco.com"
}