CVE-2020-9355: 
Linux Debian vulnerability analysis and mitigation

NetworkManager-ssh before version 1.2.11 contains a privilege escalation vulnerability (CVE-2020-9355) that was discovered in February 2020. The vulnerability affects the NetworkManager SSH VPN plugin and allows local users with privileges to modify connections to execute arbitrary commands as root due to mishandling of extra SSH options (NVD, Ubuntu).

The vulnerability stems from improper handling of extra SSH options in the NetworkManager-ssh plugin. The issue was assigned a CVSS v3.1 base score of 9.8 (Critical) with the following metrics: Attack Vector: Network, Attack Complexity: Low, Privileges Required: None, User Interaction: None, Scope: Unchanged, and Impact scores (Confidentiality/Integrity/Availability) all rated as High (Ubuntu).

The vulnerability allows local users with privileges to modify a connection to execute arbitrary commands with root privileges, effectively enabling privilege escalation on affected systems (Debian).

The vulnerability was fixed in NetworkManager-ssh version 1.2.11 by completely removing support for extra SSH options. For Debian systems, fixes were released as version 1.2.1-1+deb9u1 for oldstable (stretch) and version 1.2.10-1+deb10u1 for stable (buster) distributions (Debian).