CVE-2023-28450Network attack vector

DNS service interruption via oversized EDNS UDP packets

Published Mar 15, 2023 · Updated Nov 3, 2025

Denial of service in Dnsmasq before 2.90 allows remote attackers to interrupt DNS resolution through fragmented EDNS.0 UDP traffic. The EDNS_PKTSZ constant in src/config.h sets the forwarder's default maximum UDP packet size to 4096 bytes, causing IP fragmentation instead of using the 1232-byte safe size. Exploitation requires network access and crafted fragmented UDP traffic; fragment loss can make DNS replies unreliable and interrupt resolution.

CVSS severity7.5
High
EPSS probability1.77%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Dnsmasq before 2.90 allows remote attackers to interrupt DNS resolution through fragmented EDNS.0 UDP traffic. The EDNS_PKTSZ constant in src/config.h sets the forwarder's default maximum UDP packet size to 4096 bytes, causing IP fragmentation instead of using the 1232-byte safe size. Exploitation requires network access and crafted fragmented UDP traffic; fragment loss can make DNS replies unreliable and interrupt resolution.

The record

CVE
CVE-2023-28450
Published
Mar 15, 2023
Updated
Nov 3, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CAPEC-495, T1498
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 15, 2023CVE publishedPublication date reported by the CVE source.
  2. Nov 3, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

5.9Amazon LinuxCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
7.5NVDCVSS:3.1/AV:N/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.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CAPEC-495UDP Fragmentation
T1498Network Denial of Service

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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