CVE-2020-15703: 
Python vulnerability analysis and mitigation

Aptdaemon, a transaction-based package management service, was found to contain a vulnerability identified as CVE-2020-15703. The vulnerability was discovered by Vaisha Bernard and affected Ubuntu systems. The issue was related to incorrect handling of the Locale property in Aptdaemon (Ubuntu Notice).

The vulnerability stems from improper handling of the Locale property in Aptdaemon. This vulnerability is similar in nature to other file existence disclosure vulnerabilities found in the same software. The issue allows for testing the presence of local files through specific property manipulations (GitHub Security Lab).

The vulnerability allows local attackers to test for the presence of files on the system, potentially exposing sensitive information about the system's file structure (Ubuntu Notice).

The vulnerability can be exploited by local attackers to probe for the existence of files, including those in directories that are typically only readable by root users (GitHub Security Lab).

The vulnerability was addressed through system updates. Ubuntu released fixed versions: Ubuntu 20.04: aptdaemon - 1.1.1+bzr982-0ubuntu32.2, Ubuntu 18.04: aptdaemon - 1.1.1+bzr982-0ubuntu19.4, and Ubuntu 16.04: aptdaemon - 1.1.1+bzr982-0ubuntu14.4. Users need to perform a standard system update and reboot their computer to implement all necessary changes (Ubuntu Notice).