USN-4374-1: Unbound vulnerabilities

Publication date

27 May 2020

Overview

Several security issues were fixed in Unbound.


Packages

  • unbound - validating, recursive, caching DNS resolver

Details

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)

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

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

Learn more about how to get the fixes.

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

Ubuntu Release Package Version
20.04 focal libunbound8 –  1.9.4-2ubuntu1.1
unbound –  1.9.4-2ubuntu1.1
19.10 eoan libunbound8 –  1.9.0-2ubuntu1.1
unbound –  1.9.0-2ubuntu1.1
18.04 bionic libunbound2 –  1.6.7-1ubuntu2.3
unbound –  1.6.7-1ubuntu2.3

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