--- title: 'USN-6584-2: Libspf2 vulnerabilities | Ubuntu security notices' description: Ubuntu is an open source software operating system that runs from the desktop, to the cloud, to all your internet connected things. url: https://ubuntu.com/security/notices/USN-6584-2 --- 1. [Ubuntu Security Notices](https://ubuntu.com/security/notices) 2. USN-6584-2 --- # USN-6584-2: Libspf2 vulnerabilities Publication date 21 February 2024 Overview Several security issues were fixed in Libspf2. Releases [16.04 LTS](https://ubuntu.com/security/notices?release=xenial) --- Open side navigation ## Packages * [libspf2](https://ubuntu.com/security/cves?package=libspf2) - Sender Policy Framework for SMTP authorization ## Details USN-6584-1 fixed several vulnerabilities in Ubuntu 18.04 LTS and Ubuntu 20.04 LTS. This update provides the corresponding updates for [CVE-2021-33912](https://ubuntu.com/security/CVE-2021-33912) and [CVE-2021-33913](https://ubuntu.com/security/CVE-2021-33913) in Ubuntu 16.04 LTS. We apologize for the inconvenience. Original advisory details: Philipp Jeitner and Haya Shulman discovered that Libspf2 incorrectly handled certain inputs. If a user or an automated system were tricked into opening a specially crafted input file, a remote attacker could possibly use this issue to cause a denial of service or execute arbitrary code. ([CVE-2021-20314](https://ubuntu.com/security/CVE-2021-20314)) It was discovered that Libspf2 incorrectly handled certain inputs. If a user or an automated system were tricked into opening a specially crafted input file, a remote attacker could possibly use this issue to cause a denial of service or execute... --- Show more ## Update instructions In general, a standard system update will make all the necessary changes. [Learn more about how to get the fixes.](https://ubuntu.com/security/cves/about#security) The problem can be corrected by updating your system to the following package versions: | Ubuntu Release | Package Version | | --- | --- | | 16.04 LTS xenial | [libmail-spf-xs-perl](https://launchpad.net/ubuntu/+source/libspf2) –  1.2.10-6ubuntu0.1~esm2   Ubuntu Pro | | | | [libspf2-2](https://launchpad.net/ubuntu/+source/libspf2) –  1.2.10-6ubuntu0.1~esm2   Ubuntu Pro | | | | [libspf2-dev](https://launchpad.net/ubuntu/+source/libspf2) –  1.2.10-6ubuntu0.1~esm2   Ubuntu Pro | | | | [spfquery](https://launchpad.net/ubuntu/+source/libspf2) –  1.2.10-6ubuntu0.1~esm2   Ubuntu Pro | | | --- ### Reduce your security exposure Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines. [Get Ubuntu Pro](https://ubuntu.com/pro) ## References * [CVE-2021-33913](https://ubuntu.com/security/CVE-2021-33913) * [CVE-2021-33912](https://ubuntu.com/security/CVE-2021-33912) ## Related notices * [USN-6584-1](https://ubuntu.com/security/notices/USN-6584-1)