ASA-2019-00504 – Wind River VxWorks: Logical flaw in IPv4 assignment by the ipdhcpc DHCP client

The VxWorks DHCP client fails to properly validate that the offered IP-address in a DHCP renewal or offer response contains a valid unicast address. An attacker may assign multicast or broadcast addresses to the victim. An attacker residing on the LAN may choose to highjack a DHCP-client session that requests an IPv4 address. The attacker can send a multicast IP address in the DHCP offer/ack message, which the victim system then incorrectly assigns. This vulnerability is not very useful in isolation, but can be combined with CVE-2019-12259 to create a denial-ofservice attack.

ASA-2019-00497 – Wind River VxWorks: Heap overflow in DHCP Offer/ACK parsing in ipdhcpc

A specially crafted DHCP packet may cause overflow of heap-allocated memory on VxWorks system using DHCP. The attacker must share LAN with the device as DHCP packets is not forwarded by IP-routers. This vulnerability only affects systems that use the included DHCP client. DHCP packets may go past the local area network (LAN) via DHCP relays, but is otherwise confined to the LAN. The DHCP client may be used in VxWorks and in the bootrom. Bootrom using DHCP/BOOTP is only vulnerable during the boot process, not after the VxWorks image has booted. This defect may be used to overwrite the heap, which most likely results in a crash later on a task requesting memory from the heap. In the worst-case scenario, this vulnerability can potentially lead to RCE.