The DHCP client (udhcpc) in BusyBox before 1.20.0 allows remote DHCP servers to execute arbitrary commands via shell metacharacters in the (1) HOSTNAME, (2) DOMAINNAME, (3) NISDOMAIN, and (4) TFTPSERVER_NAME host name options.
{ "availability": "No subscription required", "ubuntu_priority": "negligible", "binaries": [ { "binary_name": "busybox", "binary_version": "1:1.21.0-1ubuntu1" }, { "binary_name": "busybox-initramfs", "binary_version": "1:1.21.0-1ubuntu1" }, { "binary_name": "busybox-static", "binary_version": "1:1.21.0-1ubuntu1" }, { "binary_name": "busybox-syslogd", "binary_version": "1:1.21.0-1ubuntu1" }, { "binary_name": "busybox-udeb", "binary_version": "1:1.21.0-1ubuntu1" }, { "binary_name": "udhcpc", "binary_version": "1:1.21.0-1ubuntu1" }, { "binary_name": "udhcpd", "binary_version": "1:1.21.0-1ubuntu1" } ] }