# CVE-2021-3502: avahi: Avahi is an implementation of the DNS Service Discovery and Multicast DNS specifications for Zero Configuration Netwo... CVE-2021-3502 is fixed in 26 products on 1 platform, first by avahi-autoipd 0.8-5ubuntu4, released May 7, 2021. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2021-3502 - Priority: Routine - CVSS: 5.5 (Moderate) - EPSS: 0.0037 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: May 7, 2021 ## Description Avahi is an implementation of the DNS Service Discovery and Multicast DNS specifications for Zero Configuration Networking. It facilitates service discovery on a local network. Avahi and Avahi-aware applications allow you to plug your computer into a network and, with no configuration, view other people to chat with, view printers to print with, and find shared files on other computers. Security Fix(es): * avahi: Local DoS by event-busy-loop from writing long lines to /run/avahi-daemon/socket (CVE-2021-3468) * avahi: reachable assertion in avahi_s_host_name_resolver_start when trying to resolve badly-formatted hostnames (CVE-2021-3502) * avahi: avahi-daemon can be crashed via DBus (CVE-2023-1981) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section. Additional Changes: For detailed information on changes in this release, see the Red Hat Enterprise Linux 9.3 Release Notes linked from the References section. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | avahi RHEL 9 | 0:0.8-15.el9 | [RHSA-2023:6707](https://patchblox.com/security/data/fix/linux/rhsa-2023-6707.md) | Nov 7, 2023 | | Linux | avahi almalinux 9 | 0.8-15.el9 | [ALSA-2023:6707](https://patchblox.com/security/data/fix/linux/alsa-2023-6707.md) | Nov 7, 2023 | | Linux | avahi ol 9 | 0:0.8-15.el9 | [ELSA-2023-6707](https://patchblox.com/security/data/fix/linux/elsa-2023-6707.md) | Nov 11, 2023 | | Linux | avahi-autoipd Ubuntu 22.04.1 LTS (jammy) | 0.8-5ubuntu4 | [avahi-autoipd 0.8-5ubuntu4](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-avahi-autoipd-0.8-5ubuntu4.md) | May 7, 2021 | | Linux | avahi-compat-howl RHEL 9 | 0:0.8-15.el9 | [RHSA-2023:6707](https://patchblox.com/security/data/fix/linux/rhsa-2023-6707.md) | Nov 7, 2023 | | Linux | avahi-compat-howl almalinux 9 | 0.8-15.el9 | [ALSA-2023:6707](https://patchblox.com/security/data/fix/linux/alsa-2023-6707.md) | Nov 7, 2023 | | Linux | avahi-compat-howl ol 9 | 0:0.8-15.el9 | [ELSA-2023-6707](https://patchblox.com/security/data/fix/linux/elsa-2023-6707.md) | Nov 11, 2023 | | Linux | avahi-compat-howl-devel RHEL 9 | 0:0.8-15.el9 | [RHSA-2023:6707](https://patchblox.com/security/data/fix/linux/rhsa-2023-6707.md) | Nov 7, 2023 | | Linux | avahi-compat-howl-devel almalinux 9 | 0.8-15.el9 | [ALSA-2023:6707](https://patchblox.com/security/data/fix/linux/alsa-2023-6707.md) | Nov 7, 2023 | | Linux | avahi-compat-howl-devel ol 9 | 0:0.8-15.el9 | [ELSA-2023-6707](https://patchblox.com/security/data/fix/linux/elsa-2023-6707.md) | Nov 11, 2023 | | Linux | avahi-compat-libdns_sd RHEL 9 | 0:0.8-15.el9 | [RHSA-2023:6707](https://patchblox.com/security/data/fix/linux/rhsa-2023-6707.md) | Nov 7, 2023 | | Linux | avahi-compat-libdns_sd almalinux 9 | 0.8-15.el9 | [ALSA-2023:6707](https://patchblox.com/security/data/fix/linux/alsa-2023-6707.md) | Nov 7, 2023 | | Linux | avahi-compat-libdns_sd ol 9 | 0:0.8-15.el9 | [ELSA-2023-6707](https://patchblox.com/security/data/fix/linux/elsa-2023-6707.md) | Nov 11, 2023 | | Linux | avahi-compat-libdns_sd-devel RHEL 9 | 0:0.8-15.el9 | [RHSA-2023:6707](https://patchblox.com/security/data/fix/linux/rhsa-2023-6707.md) | Nov 7, 2023 | | Linux | avahi-compat-libdns_sd-devel almalinux 9 | 0.8-15.el9 | [ALSA-2023:6707](https://patchblox.com/security/data/fix/linux/alsa-2023-6707.md) | Nov 7, 2023 | | Linux | avahi-compat-libdns_sd-devel ol 9 | 0:0.8-15.el9 | [ELSA-2023-6707](https://patchblox.com/security/data/fix/linux/elsa-2023-6707.md) | Nov 11, 2023 | | Linux | avahi-daemon Ubuntu 22.04.1 LTS (jammy) | 0.8-5ubuntu4 | [avahi-daemon 0.8-5ubuntu4](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-avahi-daemon-0.8-5ubuntu4.md) | May 7, 2021 | | Linux | avahi-devel RHEL 9 | 0:0.8-15.el9 | [RHSA-2023:6707](https://patchblox.com/security/data/fix/linux/rhsa-2023-6707.md) | Nov 7, 2023 | | Linux | avahi-devel almalinux 9 | 0.8-15.el9 | [ALSA-2023:6707](https://patchblox.com/security/data/fix/linux/alsa-2023-6707.md) | Nov 7, 2023 | | Linux | avahi-devel ol 9 | 0:0.8-15.el9 | [ELSA-2023-6707](https://patchblox.com/security/data/fix/linux/elsa-2023-6707.md) | Nov 11, 2023 | | Linux | avahi-discover Ubuntu 22.04.1 LTS (jammy) | 0.8-5ubuntu4 | [avahi-discover 0.8-5ubuntu4](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-avahi-discover-0.8-5ubuntu4.md) | May 7, 2021 | | Linux | avahi-dnsconfd Ubuntu 22.04.1 LTS (jammy) | 0.8-5ubuntu4 | [avahi-dnsconfd 0.8-5ubuntu4](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-avahi-dnsconfd-0.8-5ubuntu4.md) | May 7, 2021 | | Linux | avahi-glib RHEL 9 | 0:0.8-15.el9 | [RHSA-2023:6707](https://patchblox.com/security/data/fix/linux/rhsa-2023-6707.md) | Nov 7, 2023 | | Linux | avahi-glib almalinux 9 | 0.8-15.el9 | [ALSA-2023:6707](https://patchblox.com/security/data/fix/linux/alsa-2023-6707.md) | Nov 7, 2023 | | Linux | avahi-glib ol 9 | 0:0.8-15.el9 | [ELSA-2023-6707](https://patchblox.com/security/data/fix/linux/elsa-2023-6707.md) | Nov 11, 2023 | | Linux | avahi-glib-devel RHEL 9 | 0:0.8-15.el9 | [RHSA-2023:6707](https://patchblox.com/security/data/fix/linux/rhsa-2023-6707.md) | Nov 7, 2023 | | Linux | avahi-glib-devel almalinux 9 | 0.8-15.el9 | [ALSA-2023:6707](https://patchblox.com/security/data/fix/linux/alsa-2023-6707.md) | Nov 7, 2023 | | Linux | avahi-glib-devel ol 9 | 0:0.8-15.el9 | [ELSA-2023-6707](https://patchblox.com/security/data/fix/linux/elsa-2023-6707.md) | Nov 11, 2023 | | Linux | avahi-libs RHEL 9 | 0:0.8-15.el9 | [RHSA-2023:6707](https://patchblox.com/security/data/fix/linux/rhsa-2023-6707.md) | Nov 7, 2023 | | Linux | avahi-libs almalinux 9 | 0.8-15.el9 | [ALSA-2023:6707](https://patchblox.com/security/data/fix/linux/alsa-2023-6707.md) | Nov 7, 2023 | | Linux | avahi-libs ol 9 | 0:0.8-15.el9 | [ELSA-2023-6707](https://patchblox.com/security/data/fix/linux/elsa-2023-6707.md) | Nov 11, 2023 | | Linux | avahi-tools RHEL 9 | 0:0.8-15.el9 | [RHSA-2023:6707](https://patchblox.com/security/data/fix/linux/rhsa-2023-6707.md) | Nov 7, 2023 | | Linux | avahi-tools almalinux 9 | 0.8-15.el9 | [ALSA-2023:6707](https://patchblox.com/security/data/fix/linux/alsa-2023-6707.md) | Nov 7, 2023 | | Linux | avahi-tools ol 9 | 0:0.8-15.el9 | [ELSA-2023-6707](https://patchblox.com/security/data/fix/linux/elsa-2023-6707.md) | Nov 11, 2023 | | Linux | avahi-ui-utils Ubuntu 22.04.1 LTS (jammy) | 0.8-5ubuntu4 | [avahi-ui-utils 0.8-5ubuntu4](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-avahi-ui-utils-0.8-5ubuntu4.md) | May 7, 2021 | | Linux | avahi-utils Ubuntu 22.04.1 LTS (jammy) | 0.8-5ubuntu4 | [avahi-utils 0.8-5ubuntu4](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-avahi-utils-0.8-5ubuntu4.md) | May 7, 2021 | | Linux | gir1.2-avahi-0.6 Ubuntu 22.04.1 LTS (jammy) | 0.8-5ubuntu4 | [gir1.2-avahi-0.6 0.8-5ubuntu4](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-gir1.2-avahi-0.6-0.8-5ubuntu4.md) | May 7, 2021 | | Linux | libavahi-client3 Ubuntu 22.04.1 LTS (jammy) | 0.8-5ubuntu4 | [libavahi-client3 0.8-5ubuntu4](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-libavahi-client3-0.8-5ubuntu4.md) | May 7, 2021 | | Linux | libavahi-common-data Ubuntu 22.04.1 LTS (jammy) | 0.8-5ubuntu4 | [libavahi-common-data 0.8-5ubuntu4](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-libavahi-common-data-0.8-5ubuntu4.md) | May 7, 2021 | | Linux | libavahi-common3 Ubuntu 22.04.1 LTS (jammy) | 0.8-5ubuntu4 | [libavahi-common3 0.8-5ubuntu4](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-libavahi-common3-0.8-5ubuntu4.md) | May 7, 2021 | | Linux | libavahi-compat-libdnssd1 Ubuntu 22.04.1 LTS (jammy) | 0.8-5ubuntu4 | [libavahi-compat-libdnssd1 0.8-5ubuntu4](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-libavahi-compat-libdnssd1-0.8-5ubuntu4.md) | May 7, 2021 | | Linux | libavahi-core7 Ubuntu 22.04.1 LTS (jammy) | 0.8-5ubuntu4 | [libavahi-core7 0.8-5ubuntu4](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-libavahi-core7-0.8-5ubuntu4.md) | May 7, 2021 | | Linux | libavahi-glib1 Ubuntu 22.04.1 LTS (jammy) | 0.8-5ubuntu4 | [libavahi-glib1 0.8-5ubuntu4](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-libavahi-glib1-0.8-5ubuntu4.md) | May 7, 2021 | | Linux | libavahi-gobject0 Ubuntu 22.04.1 LTS (jammy) | 0.8-5ubuntu4 | [libavahi-gobject0 0.8-5ubuntu4](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-libavahi-gobject0-0.8-5ubuntu4.md) | May 7, 2021 | | Linux | libavahi-ui-gtk3-0 Ubuntu 22.04.1 LTS (jammy) | 0.8-5ubuntu4 | [libavahi-ui-gtk3-0 0.8-5ubuntu4](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-libavahi-ui-gtk3-0-0.8-5ubuntu4.md) | May 7, 2021 | | Linux | python3-avahi Ubuntu 22.04.1 LTS (jammy) | 0.8-5ubuntu4 | [python3-avahi 0.8-5ubuntu4](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-python3-avahi-0.8-5ubuntu4.md) | May 7, 2021 | --- Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.