DEBIAN-CVE-2025-59529

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Source
https://security-tracker.debian.org/tracker/CVE-2025-59529
Import Source
https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2025-59529.json
JSON Data
https://api.osv.dev/v1/vulns/DEBIAN-CVE-2025-59529
Upstream
Published
2025-12-18T21:15:53.637Z
Modified
2026-04-28T20:30:43.542994Z
Severity
  • 5.5 (Medium) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
Summary
[none]
Details

Avahi is a system which facilitates service discovery on a local network via the mDNS/DNS-SD protocol suite. In versions up to and including 0.9-rc2, the simple protocol server ignores the documented client limit and accepts unlimited connections, allowing for easy local DoS. Although CLIENTS_MAX is defined, server_work() unconditionally accept()s and client_new() always appends the new client and increments n_clients. There is no check against the limit. When client cannot be accepted as a result of maximal socket number of avahi-daemon, it logs unconditionally error per each connection. Unprivileged local users can exhaust daemon memory and file descriptors, causing a denial of service system-wide for mDNS/DNS-SD. Exhausting local file descriptors causes increased system load caused by logging errors of each of request. Overloading prevents glibc calls using nss-mdns plugins to resolve *.local. names and link-local addresses. As of time of publication, no known patched versions are available, but a candidate fix is available in pull request 808, and some workarounds are available. Simple clients are offered for nss-mdns package functionality. It is not possible to disable the unix socket /run/avahi-daemon/socket, but resolution requests received via DBus are not affected directly. Tools avahi-resolve, avahi-resolve-address and avahi-resolve-host-name are not affected, they use DBus interface. It is possible to change permissions of unix socket after avahi-daemon is started. But avahi-daemon does not provide any configuration for it. Additional access restrictions like SELinux can also prevent unwanted tools to access the socket and keep resolution working for trusted users.

References

Affected packages

Debian:11 / avahi

Package

Name
avahi
Purl
pkg:deb/debian/avahi?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

0.*
0.8-5
0.8-5+deb11u1
0.8-5+deb11u2
0.8-5+deb11u3
0.8-6
0.8-7
0.8-8
0.8-9
0.8-10
0.8-11
0.8-12
0.8-13
0.8-14
0.8-15
0.8-16
0.8-17
0.8-18

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Database specific

source 
"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2025-59529.json"

Debian:12 / avahi

Package

Name
avahi
Purl
pkg:deb/debian/avahi?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

0.*
0.8-10
0.8-10+deb12u1
0.8-11
0.8-12
0.8-13
0.8-14
0.8-15
0.8-16
0.8-17
0.8-18

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Database specific

source 
"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2025-59529.json"

Debian:13 / avahi

Package

Name
avahi
Purl
pkg:deb/debian/avahi?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

0.*
0.8-16
0.8-17
0.8-18

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Database specific

source 
"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2025-59529.json"

Debian:14 / avahi

Package

Name
avahi
Purl
pkg:deb/debian/avahi?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

0.*
0.8-16
0.8-17
0.8-18

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Database specific

source 
"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2025-59529.json"