Mageia 2021-0231: dnsmasq security update
Summary
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 (CVE-2021-3448).
This kind of configuration is the default when network-manager uses dnsmasq.
References
- https://bugs.mageia.org/show_bug.cgi?id=29030
- https://bugzilla.redhat.com/show_bug.cgi?id=1939368
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/thread/GHURNEHHUBSW45KMIZ4FNBCSUPWPGV5V/
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-3448
Resolution
MGASA-2021-0231 - Updated dnsmasq packages fix a security vulnerability
SRPMS
- 7/core/dnsmasq-2.85-1.mga7
- 8/core/dnsmasq-2.85-1.mga8