CVE-2022-30699

NLnet Labs Unbound, up to and including version 1.16.1, is vulnerable to a
novel type of the “ghost domain names” attack. The vulnerability works by
targeting an Unbound instance. Unbound is queried for a rogue domain name
when the cached delegation information is about to expire. The rogue
nameserver delays the response so that the cached delegation information is
expired. Upon receiving the delayed answer containing the delegation
information, Unbound overwrites the now expired entries. This action can be
repeated when the delegation information is about to expire making the
rogue delegation information ever-updating. From version 1.16.2 on, Unbound
stores the start time for a query and uses that to decide if the cached
delegation information can be overwritten.

Bugs

• <http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1016493&gt;

Notes