CVE-2020-15238

Blueman is a GTK+ Bluetooth Manager. In Blueman before 2.1.4, the
DhcpClient method of the D-Bus interface to blueman-mechanism is prone to
an argument injection vulnerability. The impact highly depends on the
system configuration. If Polkit-1 is disabled and for versions lower than
2.0.6, any local user can possibly exploit this. If Polkit-1 is enabled for
version 2.0.6 and later, a possible attacker needs to be allowed to use the
org.blueman.dhcp.client action. That is limited to users in the wheel
group in the shipped rules file that do have the privileges anyway. On
systems with ISC DHCP client (dhclient), attackers can pass arguments to
ip link with the interface name that can e.g. be used to bring down an
interface or add an arbitrary XDP/BPF program. On systems with dhcpcd and
without ISC DHCP client, attackers can even run arbitrary scripts by
passing -c/path/to/script as an interface name. Patches are included in
2.1.4 and master that change the DhcpClient D-Bus method(s) to accept BlueZ
network object paths instead of network interface names. A backport to
2.0(.8) is also available. As a workaround, make sure that Polkit-1-support
is enabled and limit privileges for the org.blueman.dhcp.client action to
users that are able to run arbitrary commands as root anyway in
/usr/share/polkit-1/rules.d/blueman.rules.

Bugs

• <https://bugs.launchpad.net/ubuntu/+source/blueman/+bug/1897287&gt;

Notes