| Name | CVE-2021-3448 |
| Description | A flaw was found in dnsmasq in versions before 2.85. When configured to use a specific server for a given network interface, dnsmasq uses a fixed port while forwarding queries. An attacker on the network, able to find the outgoing port used by dnsmasq, only needs to guess the random transmission ID to forge a reply and get it accepted by dnsmasq. This flaw makes a DNS Cache Poisoning attack much easier. The highest threat from this vulnerability is to data integrity. |
| Source | CVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| References | ELA-1152-1 |
Vulnerable and fixed packages
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|
| dnsmasq (PTS) | jessie, jessie (lts) | 2.72-3+deb8u7 | vulnerable |
| stretch (security) | 2.76-5+deb9u3 | vulnerable |
| stretch (lts), stretch | 2.76-5+deb9u4 | vulnerable |
| buster, buster (lts) | 2.80-1+deb10u2 | fixed |
| buster (security) | 2.80-1+deb10u1 | vulnerable |
| bullseye | 2.85-1 | fixed |
| bookworm | 2.89-1 | fixed |
| sid, trixie | 2.90-4 | fixed |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|
| dnsmasq | source | buster | 2.80-1+deb10u2 | | ELA-1152-1 | |
| dnsmasq | source | (unstable) | 2.85-1 | | | |
Notes
[buster] - dnsmasq <postponed> (Revisit once upstream has backported to 2.80)
[stretch] - dnsmasq <postponed> (Probably easier to base the patch on a backported version)
https://bugzilla.redhat.com/show_bug.cgi?id=1939368
https://thekelleys.org.uk/gitweb/?p=dnsmasq.git;a=commit;h=74d4fcd756a85bc1823232ea74334f7ccfb9d5d2
[jessie] - dnsmasq <postponed> (Probably easier to base the patch on a backported version from upstream)