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High severity · published Jan 16, 2019
CVE-2018-5733
A malicious client can overflow a reference counter in ISC dhcpd
7.5
CVSS
20.2%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)20.2% · higher than 97% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
ID
ISC DHCP · ISC
ISC DHCP 4.1.0 -> 4.1-ESV-R15, 4.2.0 -> 4.2.8, 4.3.0 -> 4.3.6, 4.4.0 · source: vendor
DL
Debian Linux · Debian
7.0; 8.0; 9.0 · source: NVD
DH
Dhcp · Isc
4.2.0 through 4.2.8; 4.3.0 through 4.3.6; 4.1-esv; 4.1-esv; 4.1-esv; 4.1-esv; +32 more · source: NVD
EL
Enterprise Linux Desktop · Redhat
6.0; 7.0 · source: NVD
EL
Enterprise Linux Server · Redhat
6.0; 7.0 · source: NVD
EL
Enterprise Linux Server Aus · Redhat
7.4; 7.6 · source: NVD
EL
Enterprise Linux Server Eus · Redhat
7.4; 7.5; 7.6 · source: NVD
EL
Enterprise Linux Workstation · Redhat
6.0; 7.0 · source: NVD
UL
Ubuntu Linux · Canonical
14.04; 16.04; 17.10 · source: NVD
Affected product
ID
ISC DHCP
ISC
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2018-5733
CVE.org
https://www.cve.org/CVERecord?id=CVE-2018-5733
Third Party Advisory
http://www.securityfocus.com/bid/103188
Third Party Advisory
http://www.securitytracker.com/id/1040437
Third Party Advisory
https://access.redhat.com/errata/RHSA-2018:0469
Third Party Advisory
https://access.redhat.com/errata/RHSA-2018:0483
Vendor Advisory
https://kb.isc.org/docs/aa-01567
Third Party Advisory
https://lists.debian.org/debian-lts-announce/2018/03/msg00015.html
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An option refcount overflow exists in dhcpd