--- title: 'USN-4540-1: atftpd 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-4540-1 --- 1. [Ubuntu Security Notices](https://ubuntu.com/security/notices) 2. USN-4540-1 --- # USN-4540-1: atftpd vulnerabilities Publication date 24 September 2020 Overview Several security issues were fixed in atftpd. Releases [18.04 LTS](https://ubuntu.com/security/notices?release=bionic) --- Open side navigation ## Packages * [atftp](https://ubuntu.com/security/cves?package=atftp) - Advanced TFTP Server and Client ## Details Denis Andzakovic discovered that atftpd incorrectly handled certain malformed packets. A remote attacker could send a specially crafted packet to cause atftpd to crash, resulting in a denial of service. ([CVE-2019-11365](https://ubuntu.com/security/CVE-2019-11365)) Denis Andzakovic discovered that atftpd did not properly lock the thread list mutex. An attacker could send a large number of tftpd packets simultaneously when running atftpd in daemon mode to cause atftpd to crash, resulting in a denial of service. ([CVE-2019-11366](https://ubuntu.com/security/CVE-2019-11366)) ## 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 | | --- | --- | | 18.04 LTS bionic | [atftpd](https://launchpad.net/ubuntu/+source/atftp) –  [0.7.git20120829-3.1~0.18.04.1](https://launchpad.net/ubuntu/+source/atftp/0.7.git20120829-3.1~0.18.04.1) | | | --- ### 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-2019-11366](https://ubuntu.com/security/CVE-2019-11366) * [CVE-2019-11365](https://ubuntu.com/security/CVE-2019-11365) ## Related notices * [USN-4643-1](https://ubuntu.com/security/notices/USN-4643-1)