{"id":"CVE-2018-5733","state":"PUBLISHED","title":"A malicious client can overflow a reference counter in ISC dhcpd","description":"A malicious client which is allowed to send very large amounts of traffic (billions of packets) to a DHCP server can eventually overflow a 32-bit reference counter, potentially causing dhcpd to crash. Affects ISC DHCP 4.1.0 -> 4.1-ESV-R15, 4.2.0 -> 4.2.8, 4.3.0 -> 4.3.6, 4.4.0.","publishedAt":"2019-01-16T20:00:00.000Z","updatedAt":"2025-04-25T23:02:52.084Z","severity":{"score":5.9,"label":"Medium","version":"3.0","vector":"CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"isc"},"assigner":"isc","products":["ISC ISC DHCP"],"affected":[{"vendor":"ISC","product":"ISC DHCP","versions":[{"version":"ISC DHCP 4.1.0 -> 4.1-ESV-R15, 4.2.0 -> 4.2.8, 4.3.0 -> 4.3.6, 4.4.0","status":"affected"}]}],"references":["https://kb.isc.org/docs/aa-01567","https://access.redhat.com/errata/RHSA-2018:0469","https://www.debian.org/security/2018/dsa-4133","https://usn.ubuntu.com/3586-2/","https://access.redhat.com/errata/RHSA-2018:0483","https://usn.ubuntu.com/3586-1/","http://www.securityfocus.com/bid/103188","http://www.securitytracker.com/id/1040437","https://lists.debian.org/debian-lts-announce/2018/03/msg00015.html","https://security.netapp.com/advisory/ntap-20250425-0010/"],"weaknesses":[],"ingestedAt":"2026-10-29T19:44:56.034Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2018/5xxx/CVE-2018-5733.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.1","cveMetadata":{"cveId":"CVE-2018-5733","state":"PUBLISHED","datePublished":"2019-01-16T20:00:00.000Z","dateUpdated":"2025-04-25T23:02:52.084Z","assignerShortName":"isc","assignerOrgId":"404fd4d2-a609-4245-b543-2c944a302a22","dateReserved":"2018-01-17T00:00:00.000Z"},"containers":{"cna":{"title":"A malicious client can overflow a reference counter in ISC dhcpd","descriptions":[{"lang":"en","value":"A malicious client which is allowed to send very large amounts of traffic (billions of packets) to a DHCP server can eventually overflow a 32-bit reference counter, potentially causing dhcpd to crash. Affects ISC DHCP 4.1.0 -> 4.1-ESV-R15, 4.2.0 -> 4.2.8, 4.3.0 -> 4.3.6, 4.4.0."}],"affected":[{"vendor":"ISC","product":"ISC DHCP","versions":[{"version":"ISC DHCP 4.1.0 -> 4.1-ESV-R15, 4.2.0 -> 4.2.8, 4.3.0 -> 4.3.6, 4.4.0","status":"affected"}]}],"references":[{"url":"https://kb.isc.org/docs/aa-01567","tags":["x_refsource_CONFIRM"]},{"url":"https://access.redhat.com/errata/RHSA-2018:0469","name":"RHSA-2018:0469","tags":["vendor-advisory","x_refsource_REDHAT"]},{"url":"https://www.debian.org/security/2018/dsa-4133","name":"DSA-4133","tags":["vendor-advisory","x_refsource_DEBIAN"]},{"url":"https://usn.ubuntu.com/3586-2/","name":"USN-3586-2","tags":["vendor-advisory","x_refsource_UBUNTU"]},{"url":"https://access.redhat.com/errata/RHSA-2018:0483","name":"RHSA-2018:0483","tags":["vendor-advisory","x_refsource_REDHAT"]},{"url":"https://usn.ubuntu.com/3586-1/","name":"USN-3586-1","tags":["vendor-advisory","x_refsource_UBUNTU"]},{"url":"http://www.securityfocus.com/bid/103188","name":"103188","tags":["vdb-entry","x_refsource_BID"]},{"url":"http://www.securitytracker.com/id/1040437","name":"1040437","tags":["vdb-entry","x_refsource_SECTRACK"]},{"url":"https://lists.debian.org/debian-lts-announce/2018/03/msg00015.html","name":"[debian-lts-announce] 20180322 [SECURITY] [DLA 1313-1] isc-dhcp security update","tags":["mailing-list","x_refsource_MLIST"]}],"metrics":[{"cvssV3_0":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":5.9,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.0"}}],"problemTypes":[{"descriptions":[{"description":"Successful exploitation of this vulnerability may exhaust the memory available to dhcpd and/or cause it to crash, resulting in a denial of service to clients.","lang":"en","type":"text"}]}],"providerMetadata":{"shortName":"isc","dateUpdated":"2019-01-17T10:57:01.000Z","orgId":"404fd4d2-a609-4245-b543-2c944a302a22"},"credits":[{"lang":"en","value":"ISC would like to thank Felix Wilhelm, Google Security Team, for reporting this vulnerability."}],"datePublic":"2018-02-28T00:00:00.000Z","solutions":[{"lang":"en","value":"Upgrade to the patched release most closely related to your current version of DHCP.\n\n    DHCP 4.1-ESV-R15-P1\n    DHCP 4.3.6-P1\n    DHCP 4.4.1"}],"source":{"discovery":"EXTERNAL"},"x_legacyV4Record":{"CVE_data_meta":{"ASSIGNER":"security-officer@isc.org","DATE_PUBLIC":"2018-02-28T00:00:00.000Z","ID":"CVE-2018-5733","STATE":"PUBLIC","TITLE":"A malicious client can overflow a reference counter in ISC dhcpd"},"affects":{"vendor":{"vendor_data":[{"product":{"product_data":[{"product_name":"ISC DHCP","version":{"version_data":[{"version_name":"ISC DHCP","version_value":"4.1.0 -> 4.1-ESV-R15, 4.2.0 -> 4.2.8, 4.3.0 -> 4.3.6, 4.4.0"}]}}]},"vendor_name":"ISC"}]}},"credit":[{"lang":"eng","value":"ISC would like to thank Felix Wilhelm, Google Security Team, for reporting this vulnerability."}],"data_format":"MITRE","data_type":"CVE","data_version":"4.0","description":{"description_data":[{"lang":"eng","value":"A malicious client which is allowed to send very large amounts of traffic (billions of packets) to a DHCP server can eventually overflow a 32-bit reference counter, potentially causing dhcpd to crash. Affects ISC DHCP 4.1.0 -> 4.1-ESV-R15, 4.2.0 -> 4.2.8, 4.3.0 -> 4.3.6, 4.4.0."}]},"impact":{"cvss":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":5.9,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.0"}},"problemtype":{"problemtype_data":[{"description":[{"lang":"eng","value":"Successful exploitation of this vulnerability may exhaust the memory available to dhcpd and/or cause it to crash, resulting in a denial of service to clients."}]}]},"references":{"reference_data":[{"name":"https://kb.isc.org/docs/aa-01567","refsource":"CONFIRM","url":"https://kb.isc.org/docs/aa-01567"},{"name":"RHSA-2018:0469","refsource":"REDHAT","url":"https://access.redhat.com/errata/RHSA-2018:0469"},{"name":"DSA-4133","refsource":"DEBIAN","url":"https://www.debian.org/security/2018/dsa-4133"},{"name":"USN-3586-2","refsource":"UBUNTU","url":"https://usn.ubuntu.com/3586-2/"},{"name":"RHSA-2018:0483","refsource":"REDHAT","url":"https://access.redhat.com/errata/RHSA-2018:0483"},{"name":"USN-3586-1","refsource":"UBUNTU","url":"https://usn.ubuntu.com/3586-1/"},{"name":"103188","refsource":"BID","url":"http://www.securityfocus.com/bid/103188"},{"name":"1040437","refsource":"SECTRACK","url":"http://www.securitytracker.com/id/1040437"},{"name":"[debian-lts-announce] 20180322 [SECURITY] [DLA 1313-1] isc-dhcp security update","refsource":"MLIST","url":"https://lists.debian.org/debian-lts-announce/2018/03/msg00015.html"}]},"solution":[{"lang":"en","value":"Upgrade to the patched release most closely related to your current version of DHCP.\n\n    DHCP 4.1-ESV-R15-P1\n    DHCP 4.3.6-P1\n    DHCP 4.4.1"}],"source":{"discovery":"EXTERNAL"}}},"adp":[{"title":"CVE Program Container","references":[{"url":"https://kb.isc.org/docs/aa-01567","tags":["x_refsource_CONFIRM","x_transferred"]},{"url":"https://access.redhat.com/errata/RHSA-2018:0469","name":"RHSA-2018:0469","tags":["vendor-advisory","x_refsource_REDHAT","x_transferred"]},{"url":"https://www.debian.org/security/2018/dsa-4133","name":"DSA-4133","tags":["vendor-advisory","x_refsource_DEBIAN","x_transferred"]},{"url":"https://usn.ubuntu.com/3586-2/","name":"USN-3586-2","tags":["vendor-advisory","x_refsource_UBUNTU","x_transferred"]},{"url":"https://access.redhat.com/errata/RHSA-2018:0483","name":"RHSA-2018:0483","tags":["vendor-advisory","x_refsource_REDHAT","x_transferred"]},{"url":"https://usn.ubuntu.com/3586-1/","name":"USN-3586-1","tags":["vendor-advisory","x_refsource_UBUNTU","x_transferred"]},{"url":"http://www.securityfocus.com/bid/103188","name":"103188","tags":["vdb-entry","x_refsource_BID","x_transferred"]},{"url":"http://www.securitytracker.com/id/1040437","name":"1040437","tags":["vdb-entry","x_refsource_SECTRACK","x_transferred"]},{"url":"https://lists.debian.org/debian-lts-announce/2018/03/msg00015.html","name":"[debian-lts-announce] 20180322 [SECURITY] [DLA 1313-1] isc-dhcp security update","tags":["mailing-list","x_refsource_MLIST","x_transferred"]},{"url":"https://security.netapp.com/advisory/ntap-20250425-0010/"}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2025-04-25T23:02:52.084Z"}}]}}}