USN-4374-1: Unbound vulnerabilities

Releases

• Ubuntu 20.04 LTS
• Ubuntu 19.10
• Ubuntu 18.04 ESM

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)

Update instructions

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

Ubuntu 20.04

• libunbound8 - 1.9.4-2ubuntu1.1
• unbound - 1.9.4-2ubuntu1.1

Ubuntu 19.10

• libunbound8 - 1.9.0-2ubuntu1.1
• unbound - 1.9.0-2ubuntu1.1

Ubuntu 18.04

• libunbound2 - 1.6.7-1ubuntu2.3
• unbound - 1.6.7-1ubuntu2.3

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

References

• CVE-2020-12662
• CVE-2020-12663