Description
The originates_from_local_legacy_unicast_socket function (avahi-core/server.c) in avahi-daemon in Avahi before 0.6.24 allows remote attackers to cause a denial of service (crash) via a crafted mDNS packet with a source port of 0, which triggers an assertion failure.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | avahi | 0.6.23-3 | — |
| Debian 13 | avahi | 0.6.23-3 | — |
| Debian 12 | avahi | 0.6.23-3 | — |
| Debian 5.0 | avahi | 0.6.22-3+lenny1 | DTSA-189-1 |
| Debian 4.0 | avahi | 0.6.16-3etch2 | DSA-1690-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 5 | avahi +10 | 0.6.16-1.el5_2.1 | RHSA-2009:0013 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | avahi | 0.8-7.2 | openSUSE-SU-2024:10643-1 |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.
Metasploit 1 module
-
Avahi Source Port 0 DoS
auxiliary/dos/mdns/avahi_portzero
Exploit-DB 1
- Avahi < 0.6.24 - mDNS Daemon Remote Denial of Service EDB-7520 · dos · Dec 19, 2008 · verified
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Advisories 4
- RHSA-2009:0013 Red Hat Security Advisory: avahi security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- DSA-1690-1 avahi - denial of service Debian Security (DSA / DLA) · Mar 9, 2026
- DTSA-189-1 avahi - denial of service Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2024:10643-1 avahi-0.8-7.2 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
References
- 33220 third-party-advisory
- [oss-security] 20081214 Avahi daemon DoS (CVE-2008-5081) mailing-list
- SUSE-SR:2009:003 vendor-advisory
- 33279 third-party-advisory
- oval:org.mitre.oval:def:9987 vdb-entry signature
- USN-696-1 vendor-advisory
- DSA-1690 vendor-advisory
- 32825 vdb-entry
- 7520 exploit
- GLSA-200901-11 vendor-advisory
- 33153 third-party-advisory
- 33475 third-party-advisory
- http://avahi.org/milestone/Avahi%200.6.24