CVE-2022-2928 | An option refcount overflow exists in dhcpd

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.

Published: 2022-10-07 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2022-2928 is rated Moderate Risk (43/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.67%). Review affected assets and schedule remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2022-2928

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.07% 0.67% +0.60%
2 2026-05-09 0.05% 0.07% +0.03%
3 2026-04-08 — 0.05% —

Full EPSS history (18 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2022-2928

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:A)
Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 3.6 [email protected]
6.5 3.1 MEDIUM
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:A)
Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 2.8 3.6 [email protected]

Weakness enumeration for CVE-2022-2928

OS Trackers for CVE-2022-2928

vendor priority summary link
alpine medium CVE-2022-2928: 1 source package rows (dhcp); 11 state rows across 5 repos (3.17-main, 3.18-main, 3.19-main, 3.20-main, edge-main); fixed 5, open 6. https://security.alpinelinux.org/vuln/CVE-2022-2928
debian not yet assigned CVE-2022-2928 not yet assigned priority: Debian including 1 source packages (isc-dhcp), 4 status rows across 4 suites (bookworm, bullseye, sid, trixie): resolved 4. https://security-tracker.debian.org/tracker/CVE-2022-2928
gentoo normal CVE-2022-2928: 1 GLSA(s) (202305-22), 1 atom(s) (net-misc/dhcp); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2022-2928
redhat medium — https://access.redhat.com/security/cve/CVE-2022-2928
suse medium CVE-2022-2928 severity moderate: SUSE including 270 source package names (1.1.1.23.352:dhcp-4.3.6.P1-150000.6.17.1, 1.1.1.23.352:dhcp-client-4.3.6.P1-150000.6.17.1, …), 841 product×package rows across 292 product lines (Container suse/sles/15.6/libguestfs-tools, Container suse/sles/15.7/libguestfs-tools, … (292 product lines)): Fixed 684, Known Affected 157. https://www.suse.com/security/cve/CVE-2022-2928/
ubuntu medium CVE-2022-2928 medium priority: Ubuntu including 1 source packages (isc-dhcp), 7 status rows across 7 suites (bionic, focal, jammy, kinetic, trusty, upstream, xenial): released 7. https://ubuntu.com/security/CVE-2022-2928

Affected software / configurations for CVE-2022-2928

Vendor Product Version Raw CPE
isc dhcp >= 4.4.0, <= 4.4.3 cpe:2.3:a:isc:dhcp:*:*:*:*:*:*:*:*
isc dhcp 4.1-esv cpe:2.3:a:isc:dhcp:4.1-esv:r1:*:*:*:*:*:*
isc dhcp 4.1-esv cpe:2.3:a:isc:dhcp:4.1-esv:r10:*:*:*:*:*:*
isc dhcp 4.1-esv cpe:2.3:a:isc:dhcp:4.1-esv:r10_b1:*:*:*:*:*:*
isc dhcp 4.1-esv cpe:2.3:a:isc:dhcp:4.1-esv:r10_rc1:*:*:*:*:*:*
isc dhcp 4.1-esv cpe:2.3:a:isc:dhcp:4.1-esv:r10b1:*:*:*:*:*:*
isc dhcp 4.1-esv cpe:2.3:a:isc:dhcp:4.1-esv:r10rc1:*:*:*:*:*:*
isc dhcp 4.1-esv cpe:2.3:a:isc:dhcp:4.1-esv:r11:*:*:*:*:*:*
isc dhcp 4.1-esv cpe:2.3:a:isc:dhcp:4.1-esv:r11_b1:*:*:*:*:*:*
isc dhcp 4.1-esv cpe:2.3:a:isc:dhcp:4.1-esv:r11_rc1:*:*:*:*:*:*
isc dhcp 4.1-esv cpe:2.3:a:isc:dhcp:4.1-esv:r11_rc2:*:*:*:*:*:*
isc dhcp 4.1-esv cpe:2.3:a:isc:dhcp:4.1-esv:r11b1:*:*:*:*:*:*
isc dhcp 4.1-esv cpe:2.3:a:isc:dhcp:4.1-esv:r11rc1:*:*:*:*:*:*
isc dhcp 4.1-esv cpe:2.3:a:isc:dhcp:4.1-esv:r11rc2:*:*:*:*:*:*
isc dhcp 4.1-esv cpe:2.3:a:isc:dhcp:4.1-esv:r12:*:*:*:*:*:*
isc dhcp 4.1-esv cpe:2.3:a:isc:dhcp:4.1-esv:r12-p1:*:*:*:*:*:*
isc dhcp 4.1-esv cpe:2.3:a:isc:dhcp:4.1-esv:r12_b1:*:*:*:*:*:*
isc dhcp 4.1-esv cpe:2.3:a:isc:dhcp:4.1-esv:r12_p1:*:*:*:*:*:*
isc dhcp 4.1-esv cpe:2.3:a:isc:dhcp:4.1-esv:r12b1:*:*:*:*:*:*
isc dhcp 4.1-esv cpe:2.3:a:isc:dhcp:4.1-esv:r13:*:*:*:*:*:*
isc dhcp 4.1-esv cpe:2.3:a:isc:dhcp:4.1-esv:r13_b1:*:*:*:*:*:*
isc dhcp 4.1-esv cpe:2.3:a:isc:dhcp:4.1-esv:r13b1:*:*:*:*:*:*
isc dhcp 4.1-esv cpe:2.3:a:isc:dhcp:4.1-esv:r14:*:*:*:*:*:*
isc dhcp 4.1-esv cpe:2.3:a:isc:dhcp:4.1-esv:r14_b1:*:*:*:*:*:*
isc dhcp 4.1-esv cpe:2.3:a:isc:dhcp:4.1-esv:r14b1:*:*:*:*:*:*
isc dhcp 4.1-esv cpe:2.3:a:isc:dhcp:4.1-esv:r15:*:*:*:*:*:*
isc dhcp 4.1-esv cpe:2.3:a:isc:dhcp:4.1-esv:r15-p1:*:*:*:*:*:*
isc dhcp 4.1-esv cpe:2.3:a:isc:dhcp:4.1-esv:r15_b1:*:*:*:*:*:*
isc dhcp 4.1-esv cpe:2.3:a:isc:dhcp:4.1-esv:r16:*:*:*:*:*:*
isc dhcp 4.1-esv cpe:2.3:a:isc:dhcp:4.1-esv:r16-p1:*:*:*:*:*:*
debian debian_linux 10.0 cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
fedoraproject fedora 35 cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*
fedoraproject fedora 36 cpe:2.3:o:fedoraproject:fedora:36:*:*:*:*:*:*:*
fedoraproject fedora 37 cpe:2.3:o:fedoraproject:fedora:37:*:*:*:*:*:*:*

References for CVE-2022-2928

cvelogic Threat Intelligence