NetworkManager-l2tp Privilege Escalation via pppd Username Injection
NetworkManager-l2tp through 1.52.4, fixed in 1.52.6, contains a privilege escalation vulnerability that allows local users with permission to create VPN connections to execute arbitrary code as root by injecting pppd options through a crafted VPN username. Attackers can embed a double-quote character or whitespace in the username to break out of the pppd options file quoting context and include the pppd plugin directive, causing the privileged pppd process to load an attacker-controlled shared object.
NetworkManager-l2tp Privilege Escalation via pppd Plugin Injection
NetworkManager-l2tp through 1.52.4, fixed in 1.52.6, contains an improper input validation vulnerability that allows local users with VPN connection creation permissions to inject arbitrary pppd directives by supplying mru or mtu property values containing trailing non-numeric content after a valid integer. Attackers can exploit the verbatim write of unvalidated strings into the pppd options file via write_config_option() to inject the plugin directive, causing the privileged pppd process to load an attacker-controlled shared object and achieve arbitrary code execution as root.
NetworkManager-l2tp: local privilege escalation via ipsec.conf injection
A flaw was found in NetworkManager-l2tp. The plugin writes attacker-controlled VPN connection properties (vpn.data and vpn.secrets values) unescaped into a generated ipsec.conf file that pluto loads as root. A local unprivileged user can create and activate their own L2TP VPN profile containing a newline-injected leftupdown directive; pluto executes that command as root when the IKE security association is established, resulting in local privilege escalation. This is the same bug class as CVE-2018-10900 (NetworkManager-vpnc).