Shoham Danino

The DNS message parsing code in `named` includes a section whose computational complexity is overly high. It does not cause problems for typical DNS traffic, but crafted queries and responses may cause excessive CPU load on the affected `named` instance by exploiting this flaw. This issue affects both authoritative servers and recursive resolvers. A remote attacker could exploit this vulnerability to trigger an assertion failure by querying RFC 1918 reverse zones.

The effectiveness of the cache-cleaning algorithm used in `named` can be severely diminished by querying the resolver for specific RRsets in a certain order, effectively allowing the configured `max-cache-size` limit to be significantly exceeded. This can lead to a denial of service, caused by a flaw that allows the named's configured cache size limit to be significantly exceeded, potentially exhausting all memory on the host.