# CVE-2018-5732: isc-dhcp-client: Failure to properly bounds-check a buffer used for processing DHCP options allows a malicious server (or an entity ma...

CVE-2018-5732 is fixed in 6 products on 1 platform, first by isc-dhcp-client 4.3.5-3ubuntu5, released February 28, 2018. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2018-5732
- Priority: Routine
- CVSS: n/a (Medium)
- EPSS: 0.0524
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Feb 28, 2018

## Description

Failure to properly bounds-check a buffer used for processing DHCP options allows a malicious server (or an entity masquerading as a server) to cause a buffer overflow (and resulting crash) in dhclient by sending a response containing a specially constructed options section. Affects ISC DHCP versions 4.1.0 -> 4.1-ESV-R15, 4.2.0 -> 4.2.8, 4.3.0 -> 4.3.6, 4.4.0

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | isc-dhcp-client Ubuntu 18.04.6 LTS (bionic) | 4.3.5-3ubuntu5 | [isc-dhcp-client 4.3.5-3ubuntu5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-isc-dhcp-client-4.3.5-3ubuntu5.md) | Feb 28, 2018 |
| Linux | isc-dhcp-client-ddns Ubuntu 18.04.6 LTS (bionic) | 4.3.5-3ubuntu5 | [isc-dhcp-client-ddns 4.3.5-3ubuntu5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-isc-dhcp-client-ddns-4.3.5-3ubuntu5.md) | Feb 28, 2018 |
| Linux | isc-dhcp-common Ubuntu 18.04.6 LTS (bionic) | 4.3.5-3ubuntu5 | [isc-dhcp-common 4.3.5-3ubuntu5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-isc-dhcp-common-4.3.5-3ubuntu5.md) | Feb 28, 2018 |
| Linux | isc-dhcp-relay Ubuntu 18.04.6 LTS (bionic) | 4.3.5-3ubuntu5 | [isc-dhcp-relay 4.3.5-3ubuntu5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-isc-dhcp-relay-4.3.5-3ubuntu5.md) | Feb 28, 2018 |
| Linux | isc-dhcp-server Ubuntu 18.04.6 LTS (bionic) | 4.3.5-3ubuntu5 | [isc-dhcp-server 4.3.5-3ubuntu5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-isc-dhcp-server-4.3.5-3ubuntu5.md) | Feb 28, 2018 |
| Linux | isc-dhcp-server-ldap Ubuntu 18.04.6 LTS (bionic) | 4.3.5-3ubuntu5 | [isc-dhcp-server-ldap 4.3.5-3ubuntu5](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-isc-dhcp-server-ldap-4.3.5-3ubuntu5.md) | Feb 28, 2018 |

---

Data as of 2026-11-12T07:53:35Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data

Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.