CVE-2019-3701: Canonical Ubuntu Linux

Medium severity, CVSS 4.4. EPSS: 0.7% chance of exploitation in the next 30 days.

An issue was discovered in can_can_gw_rcv in net/can/gw.c in the Linux kernel through 4.19.13. The CAN frame modification rules allow bitwise logical operations that can be also applied to the can_dlc field. The privileged user "root" with CAP_NET_ADMIN can create a CAN frame modification rule that makes the data length code a higher value than the available CAN frame data size. In combination with a configured checksum calculation where the result is stored relatively to the end of the data (e.g. cgw_csum_xor_rel) the tail of the skb (e.g. frag_list pointer in skb_shared_info) can be rewritten which finally can cause a system crash. Because of a missing check, the CAN drivers may write arbitrary content beyond the data registers in the CAN controller's I/O memory when processing can-gw manipulated outgoing frames.

Affected products

• Canonical Ubuntu Linux: version 14.04 only; version 16.04 only
• Debian Debian Linux: version 8.0 only
• Linux Linux Kernel: up to and including 4.19.13

Published 2019-01-03. Last modified 2026-06-17.