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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| ISC | ISC DHCP | ISC DHCP 4.1.0 -> 4.1-ESV-R15, 4.2.0 -> 4.2.8, 4.3.0 -> 4.3.6, 4.4.0 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 13 | isc-dhcp | 4.3.5-3.1 | — |
| Debian 12 | isc-dhcp | 4.3.5-3.1 | — |
| Debian 9 | isc-dhcp | 4.3.5-3+deb9u1 | DSA-4133-1 |
| Debian 8 | isc-dhcp | 4.3.1-6+deb8u3 | DSA-4133-1 |
| Debian 7 | isc-dhcp | 4.2.2.dfsg.1-5+deb70u9 | DLA-1313-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | isc-dhcp | 4.3.5-3ubuntu5 | — |
| Ubuntu 16.04 LTS | isc-dhcp | 4.3.3-5ubuntu12.9 | USN-3586-1 |
| Ubuntu 14.04 LTS | isc-dhcp | 4.2.4-7ubuntu12.12 | USN-3586-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7 | dhcp +4 | 12:4.2.5-58.el7_4.3 | RHSA-2018:0483 |
| RHEL 6 | dhcp +3 | 12:4.1.1-53.P1.el6_9.3 | RHSA-2018:0469 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP3 | dhcp | 4.3.3-10.14.1 | SUSE-SU-2018:0812-1 |
| SLES 12 SP2 | dhcp | 4.3.3-10.14.1 | SUSE-SU-2018:0812-1 |
| SLES 11 SP4 | dhcp | 4.2.4.P2-0.28.8.1 | SUSE-SU-2018:0810-1 |
| SLES 11 SP3 | dhcp | 4.2.4.P2-0.28.8.1 | SUSE-SU-2018:0810-2 |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 12 SP3 | dhcp | 4.3.3-10.14.1 | SUSE-SU-2018:0812-1 |
| SLES for SAP 12 SP2 | dhcp | 4.3.3-10.14.1 | SUSE-SU-2018:0812-1 |
| SLES for SAP 11 SP4 | dhcp | 4.2.4.P2-0.28.8.1 | SUSE-SU-2018:0810-1 |
| SUSE Linux Enterprise Point of Sale 11 SP3 | dhcp | 4.2.4.P2-0.28.8.1 | SUSE-SU-2018:0810-2 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | dhcp | 4.4.2.P1-2.4 | openSUSE-SU-2024:10715-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.20 | dhcp | 4.4.1-r0 | — |
| Alpine v3.19 | dhcp | 4.4.1-r0 | — |
| Alpine v3.18 | dhcp | 4.4.1-r0 | — |
| Alpine v3.17 | dhcp | 4.4.1-r0 | — |
| Alpine v3.16 | dhcp | 4.4.1-r0 | — |
Show 6 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.15 | dhcp | 4.4.1-r0 | — |
| Alpine v3.14 | dhcp | 4.4.1-r0 | — |
| Alpine v3.13 | dhcp | 4.4.1-r0 | — |
| Alpine v3.12 | dhcp | 4.4.1-r0 | — |
| Alpine v3.11 | dhcp | 4.4.1-r0 | — |
| Alpine v3.10 | dhcp | 4.4.1-r0 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | dhcp +4 | 12:4.2.5-58.amzn2.3.2 | ALAS2-2018-984 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 7 | dhcp +4 | 12:4.2.5-58.0.1.el7_4.3 | ELSA-2018-0483 |
Advisories 12
- RHSA-2018:0483 Red Hat Security Advisory: dhcp security update Red Hat Security Advisories (RHSA) · Jul 1, 2026
- RHSA-2018:0469 Red Hat Security Advisory: dhcp security update Red Hat Security Advisories (RHSA) · Jul 1, 2026
- USN-3586-1 isc-dhcp vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- DSA-4133-1 isc-dhcp - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-1313-1 isc-dhcp - security update Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2024:10715-1 dhcp-4.4.2.P1-2.4 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:0810-1 Security update for dhcp SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:0812-1 Security update for dhcp SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2018:0810-2 Security update for dhcp SUSE / openSUSE Security Updates · Feb 4, 2026
- WID-SEC-2023-0525 Internet Systems Consortium DHCP: Mehrere Schwachstellen BSI CERT-Bund (WID) · Feb 28, 2023
- ALAS2-2018-984 Important: dhcp security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Apr 5, 2018
- ELSA-2018-0483 Important: dhcp security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Mar 12, 2018
References
- https://kb.isc.org/docs/aa-01567
- RHSA-2018:0469 vendor-advisory
- DSA-4133 vendor-advisory
- USN-3586-2 vendor-advisory
- RHSA-2018:0483 vendor-advisory
- USN-3586-1 vendor-advisory
- 103188 vdb-entry
- 1040437 vdb-entry
- [debian-lts-announce] 20180322 [SECURITY] [DLA 1313-1] isc-dhcp security update mailing-list