SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2019-3701

The CAN frame modification rules allow bitwise logical operations that can be also applied to the can_dlc field.

MEDIUM 4.4EPSS 0.70%

Does this matter?

Lower severity and a low EPSS score (0.70%). Track it; it rarely justifies an emergency change on its own.

Description

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.

CVSS 3.0
4.4 MEDIUMCVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
EPSS
0.70% probability · 51th percentile
CISA KEV
Not listed
Weakness
CWE-787
Affected
linux/linux kernel · debian/debian linux · canonical/ubuntu linux
Source
cve@mitre.org

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.