CVE-2022-2929

Memory exhaustion via unreleased FQDN option buffers

Published Oct 7, 2022 · Updated Sep 16, 2024

Memory leak in ISC DHCP 1.0.0 through 4.4.3 allows remote attackers on adjacent networks to exhaust server memory with crafted DHCP packets. The fqdn_universe_decode() function allocates a buffer while decoding option 81, then returns on a label-length byte above 63 without releasing that allocation. Repeated malformed packets from a network able to reach the DHCP server accumulate leaked buffers until memory exhaustion interrupts the service.

CVSS severity6.5
Medium
EPSS probability0.64%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory leak in ISC DHCP 1.0.0 through 4.4.3 allows remote attackers on adjacent networks to exhaust server memory with crafted DHCP packets. The fqdn_universe_decode() function allocates a buffer while decoding option 81, then returns on a label-length byte above 63 without releasing that allocation. Repeated malformed packets from a network able to reach the DHCP server accumulate leaked buffers until memory exhaustion interrupts the service.

The record

CVE
CVE-2022-2929
Published
Oct 7, 2022
Updated
Sep 16, 2024
Vendor
Internet Systems Consortium
Product
ISC DHCP
Classifications
CWE-770, T1499.002
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Oct 7, 2022CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1.0 through versions before 4.1-ESV-R16-P2
  2. Affected versionversion=4.2 through versions before 4.4.3.-P1

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

Internet Systems Consortium · ISC DHCPversion=1.0 through versions before 4.1-ESV-R16-P2; version=4.2 through versions before 4.4.3.-P1

Published CVSS scores

6.5Internet Systems ConsortiumCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-770Allocation of Resources Without Limits or Throttling
T1499.002Service Exhaustion Flood

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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