CVE-2009-0758

CVE-2009-0758 is a high-severity vulnerability in Avahi Avahi-daemon with a CVSS 2.0 base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-399.

Key facts

Description

The originates_from_local_legacy_unicast_socket function in avahi-core/server.c in avahi-daemon 0.6.23 does not account for the network byte order of a port number when processing incoming multicast packets, which allows remote attackers to cause a denial of service (network bandwidth and CPU consumption) via a crafted legacy unicast mDNS query packet that triggers a multicast packet storm.

Frequently asked questions

What is CVE-2009-0758?
The originates_from_local_legacy_unicast_socket function in avahi-core/server.c in avahi-daemon 0.6.23 does not account for the network byte order of a port number when processing incoming multicast packets, which allows remote attackers to cause a denial of service (network bandwidth and CPU consumption) via a crafted legacy unicast mDNS query packet that triggers a multicast packet storm.
How severe is CVE-2009-0758?
CVE-2009-0758 has a CVSS 2.0 base score of 7.8, rated high severity.
Is CVE-2009-0758 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (79th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2009-0758?
CVE-2009-0758 affects Avahi Avahi-daemon. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2009-0758?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2009-0758 published?
CVE-2009-0758 was published on 2009-03-03 and last updated on 2026-06-16.

References

Affected products (1)

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