An extension to hooks capabilities which debuted in Kea 1.4.0 introduced a memory leak for operators who are using certain hooks library facilities. In order to support multiple requests simultaneously, Kea 1.4 added a callout handle store but unfortunately the initial implementation of this store does not properly free memory in every case. Hooks which make use of query4 or query6 parameters in their callouts can leak memory, resulting in the eventual exhaustion of available memory and subsequent failure of the server process. Affects Kea DHCP 1.4.0.
Advisories
Source ID Title
EUVD EUVD EUVD-2018-17508 An extension to hooks capabilities which debuted in Kea 1.4.0 introduced a memory leak for operators who are using certain hooks library facilities. In order to support multiple requests simultaneously, Kea 1.4 added a callout handle store but unfortunately the initial implementation of this store does not properly free memory in every case. Hooks which make use of query4 or query6 parameters in their callouts can leak memory, resulting in the eventual exhaustion of available memory and subsequent failure of the server process. Affects Kea DHCP 1.4.0.
Fixes

Solution

Upgrade to Kea 1.4.0-P1 or higher, available via https://www.isc.org/downloads.


Workaround

+ Monitoring and routinely restarting ISC Kea DHCPv4 and DHCPv6 services may be an effective mitigation for some production environments + Running a new build of Kea without any hook libraries that use the callout store is another option, though it may not be a viable option where the production environment is dependent on the other hooks that need to be omitted to avoid these symptoms. These hooks distributed by ISC do not use the callout store and are safe to use: Lease Commands, Stat Commands, Host Commands (a Kea Premium hook) and Subnet Commands (a subscriber-only hook provided to Kea support customers). + Reverting to Kea DHCP 1.3.0 may be possible for some production environments but because of differences in the database schema operators should check carefully before attempting rollback: - If using memfile storage entirely, there should not be any compatibility issues. - If using a database solution for hosts or leases, the 1.4.0 schema will be incompatible with ISC Kea 1.3.0; the database therefore must be restored from a pre-upgrade backup for this to be successful. - If you are unsure whether or not you can roll back to 1.3.0 without restoring a previous version of your database, you may send an e-mail to security-officer@isc.org describing your storage setup and we will advise.

References
History

No history.

cve-icon MITRE

Status: PUBLISHED

Assigner: isc

Published:

Updated: 2024-09-17T02:11:49.386Z

Reserved: 2018-01-17T00:00:00

Link: CVE-2018-5739

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Modified

Published: 2019-01-16T20:29:00.940

Modified: 2024-11-21T04:09:17.420

Link: CVE-2018-5739

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.