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USN-4374-1: Unbound vulnerabilities

27 May 2020

Several security issues were fixed in Unbound.



  • unbound - validating, recursive, caching DNS resolver


Lior Shafir, Yehuda Afek, and Anat Bremler-Barr discovered that Unbound
incorrectly handled certain queries. A remote attacker could use this issue
to perform an amplification attack directed at a target. (CVE-2020-12662)

It was discovered that Unbound incorrectly handled certain malformed
answers. A remote attacker could possibly use this issue to cause Unbound
to crash, resulting in a denial of service. (CVE-2020-12663)

Update instructions

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

Ubuntu 20.04
Ubuntu 19.10
Ubuntu 18.04

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