USN-7047-1: Knot Resolver vulnerabilities

Releases

• Ubuntu 20.04 LTS

Packages

• knot-resolver - caching, DNSSEC-validating DNS resolver

Details

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)

Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 20.04

• knot-resolver - 3.2.1-3ubuntu2.2

In general, a standard system update will make all the necessary changes.

References

• CVE-2019-10190
• CVE-2019-10191
• CVE-2020-12667
• CVE-2019-19331