CVE-2018-5733
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.
Does this matter?
EPSS puts the probability of exploitation in the next 30 days at 20.2%, higher than 97% of all known CVEs. Patch or mitigate before the next change window.
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 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 20.24% probability · 97th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-190
- Affected
- isc/dhcp · redhat/enterprise linux desktop · redhat/enterprise linux server · redhat/enterprise linux server aus · redhat/enterprise linux server eus · redhat/enterprise linux workstation · canonical/ubuntu linux · debian/debian linux
- Source
- security-officer@isc.org
EPSS 20.2% since 27 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- http://www.securityfocus.com/bid/103188Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1040437Third Party Advisory, VDB Entry
- https://access.redhat.com/errata/RHSA-2018:0469Third Party Advisory
- https://access.redhat.com/errata/RHSA-2018:0483Third Party Advisory
- https://kb.isc.org/docs/aa-01567Vendor Advisory
- https://lists.debian.org/debian-lts-announce/2018/03/msg00015.htmlThird Party Advisory
- https://usn.ubuntu.com/3586-1/Third Party Advisory
- https://usn.ubuntu.com/3586-2/Third Party Advisory
- https://www.debian.org/security/2018/dsa-4133Third Party Advisory
- http://www.securityfocus.com/bid/103188Third Party Advisory, VDB Entry
- http://www.securitytracker.com/id/1040437Third Party Advisory, VDB Entry
- https://access.redhat.com/errata/RHSA-2018:0469Third Party Advisory
- https://access.redhat.com/errata/RHSA-2018:0483Third Party Advisory
- https://kb.isc.org/docs/aa-01567Vendor Advisory
- https://lists.debian.org/debian-lts-announce/2018/03/msg00015.htmlThird Party Advisory
- https://security.netapp.com/advisory/ntap-20250425-0010/
- https://usn.ubuntu.com/3586-1/Third Party Advisory
- https://usn.ubuntu.com/3586-2/Third Party Advisory
- https://www.debian.org/security/2018/dsa-4133Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.