Affected: CZ.NIC knot-resolver

A vulnerability was discovered in DNS resolver component of knot resolver through version 3.2.0 before 4.1.0 which allows remote attackers to bypass DNSSEC validation for non-existence answer. NXDOMAIN answer would get passed through to the client even if its DNSSEC validation failed, instead of sending a SERVFAIL packet. Caching is not affected by this particular bug but see CVE-2019-10191.

Affected: Ubuntu:20.04:LTS: knot-resolver

Vladimír Čunát discovered that Knot Resolver incorrectly handled input during DNSSEC validation. A remote attacker could possibly use this issue to bypass certain validations. (CVE-2019-10190)

Vladimír Čunát discovered that Knot Resolver incorrectly handled input during DNSSEC validation. A remote attacker could possibly use this issue to downgrade DNSSEC-secure domains to a DNSSEC-insecure state, resulting in a domain hijacking attack. (CVE-2019-10191)

Vladimír Čunát discovered that Knot Resolver incorrectly handled certain DNS replies with many resource records. An attacker could possibly use this issue to consume system resources, resulting in a denial of service. (CVE-2019-19331)

Lior Shafir, Yehuda Afek, and Anat Bremler-Barr discovered that Knot Resolver incorrectly handled certain queries. A remote attacker could use this issue to perform an amplification attack directed at a target. (CVE-2020-12667)