| Name | CVE-2021-3502 |
| Description | A flaw was found in avahi 0.8-5. A reachable assertion is present in avahi_s_host_name_resolver_start function allowing a local attacker to crash the avahi service by requesting hostname resolutions through the avahi socket or dbus methods for invalid hostnames. The highest threat from this vulnerability is to the service availability. |
| Source | CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| Debian Bugs | 986018 |
Vulnerable and fixed packages
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|
| avahi (PTS) | jessie, jessie (lts) | 0.6.31-5+deb8u2 | fixed |
| stretch (security) | 0.6.32-2+deb9u1 | fixed |
| stretch (lts), stretch | 0.6.32-2+deb9u2 | fixed |
| buster | 0.7-4+deb10u1 | fixed |
| buster (security) | 0.7-4+deb10u3 | fixed |
| bullseye | 0.8-5+deb11u2 | fixed |
| bookworm | 0.8-10 | fixed |
| sid, trixie | 0.8-13 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|
| avahi | source | jessie | (not affected) | | | |
| avahi | source | stretch | (not affected) | | | |
| avahi | source | buster | (not affected) | | | |
| avahi | source | bullseye | 0.8-5+deb11u1 | | | |
| avahi | source | (unstable) | 0.8-6 | | | 986018 |
Notes
[buster] - avahi <not-affected> (Vulnerable code introduced later)
[stretch] - avahi <not-affected> (Vulnerable code introduced later)
https://github.com/lathiat/avahi/issues/338
Fixed by: https://github.com/lathiat/avahi/commit/9d31939e55280a733d930b15ac9e4dda4497680c
Introduced by: https://github.com/lathiat/avahi/commit/80c98fa16782e921f5b5d5c880f1d80f5c43bd49 (v0.8)
[jessie] - avahi <not-affected> (Vulnerable code introduced later)