Unbound before 1.4.13p2 attempts to free unallocated memory during processing of duplicate CNAME records in a signed zone, which allows remote DNS servers to cause a denial of service (daemon crash) via a crafted response.

validator/val_nsec3.c in Unbound before 1.4.13p2 does not properly perform proof processing for NSEC3-signed zones, which allows remote DNS servers to cause a denial of service (daemon crash) via a malformed response that lacks expected NSEC3 records, a different vulnerability than CVE-2011-4528.

Unbound before 1.4.4 does not send responses for signed zones after mishandling an unspecified query, which allows remote attackers to cause a denial of service (DNSSEC outage) via a crafted query.

Unbound before 1.4.3 does not properly align structures on 64-bit platforms, which allows remote attackers to cause a denial of service (daemon crash) via unspecified vectors.

Unbound before 1.3.4 does not properly verify signatures for NSEC3 records, which allows remote attackers to cause secure delegations to be downgraded via DNS spoofing or other DNS-related attacks in conjunction with crafted delegation responses.