CVE-2023-1981Public exploit

Local service interruption via NULL D-Bus reply

Published May 26, 2023 · Updated Nov 3, 2025

Denial of service in Avahi allows local users to crash avahi-daemon through a crafted method call on the system D-Bus. The GetAlternativeServiceName and GetAlternativeHostName handlers pass a NULL result for an empty name to avahi_dbus_respond_string instead of returning an error. Any unprivileged local user able to call the system D-Bus interface can abort the daemon and interrupt mDNS/DNS-SD service discovery.

CVSS severity5.5
Medium
EPSS probability0.39%
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 Avahi allows local users to crash avahi-daemon through a crafted method call on the system D-Bus. The GetAlternativeServiceName and GetAlternativeHostName handlers pass a NULL result for an empty name to avahi_dbus_respond_string instead of returning an error. Any unprivileged local user able to call the system D-Bus interface can abort the daemon and interrupt mDNS/DNS-SD service discovery.

The record

CVE
CVE-2023-1981
Published
May 26, 2023
Updated
Nov 3, 2025
Vendor
Avahi
Product
Avahi
Classifications
CWE-400, T1489
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. May 26, 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?

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

  1. Affected versionversion=avahi-0.7-20

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Avahi · Avahiversion=avahi-0.7-20

Published CVSS scores

5.5NIST NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
5.5CISA-ADPCVSS:3.1/AV:L/AC:L/PR:L/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1489Service Stop

Public exploit references

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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