CVE-2022-2928

An option refcount overflow exists in dhcpd

Description

In ISC DHCP 4.4.0 -> 4.4.3, ISC DHCP 4.1-ESV-R1 -> 4.1-ESV-R16-P1, when the function option_code_hash_lookup() is called from add_option(), it increases the option's refcount field. However, there is not a corresponding call to option_dereference() to decrement the refcount field. The function add_option() is only used in server responses to lease query packets. Each lease query response calls this function for several options, so eventually, the reference counters could overflow and cause the server to abort.

Remediation

Solution:

  • Upgrade to the patched release most closely related to your current version of ISC DHCP. These can all be downloaded from https://www.isc.org/downloads. 4.4.3-P1 4.1-ESV-R16-P2

Workaround:

  • Disable lease query on the server for DHCPv4 or restart the server periodically.

Category

6.5
CVSS
Severity: Medium
CVSS 3.1 •
EPSS 0.03%
Vendor Advisory fedoraproject.org Vendor Advisory fedoraproject.org Vendor Advisory fedoraproject.org Vendor Advisory gentoo.org Vendor Advisory isc.org
Affected: ISC ISC DHCP
Published at:
Updated at:

References

Link Tags
https://kb.isc.org/docs/cve-2022-2928 vendor advisory
https://lists.debian.org/debian-lts-announce/2022/10/msg00015.html third party advisory mailing list
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/QQXYCIWUDILRCNBAIMVFCSGXBRKEPB4K/ vendor advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/T6IBFH4MRRNJQVWEKILQ6I6CXWW766FX/ vendor advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2SARIK7KZ7MGQIWDRWZFAOSQSPXY4GOU/ vendor advisory
https://security.gentoo.org/glsa/202305-22 vendor advisory

Frequently Asked Questions

What is the severity of CVE-2022-2928?
CVE-2022-2928 has been scored as a medium severity vulnerability.
How to fix CVE-2022-2928?
To fix CVE-2022-2928: Upgrade to the patched release most closely related to your current version of ISC DHCP. These can all be downloaded from https://www.isc.org/downloads. 4.4.3-P1 4.1-ESV-R16-P2
Is CVE-2022-2928 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2022-2928 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2022-2928?
CVE-2022-2928 affects ISC ISC DHCP.
This platform uses data from the NIST NVD, MITRE CVE, MITRE CWE, First.org and CISA KEV but is not endorsed or certified by these entities. CVE is a registred trademark of the MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. CWE is a registred trademark of the MITRE Corporation and the authoritative source of CWE content is MITRE's CWE web site.
© 2025 Under My Watch. All Rights Reserved.