CVE-2019-18805
kernel: integer overflow in tcp_ack_update_rtt in net/ipv4/tcp_input.c
Severity
ModerateRed Hat Product Security
CVSS 3.0
Review impact separately from score.
Published · April 16, 2019
Updated · June 28, 2026
Description
A flaw was reported in the Linux kernel's TCP subsystem while calculating a packet round trip time, when a sysctl parameter (/proc/sys/net/ipv4/tcp_min_rtt_wlen) is set incorrectly. This causes an integer overflow which can lead to a denial Of service (DOS) attack.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
This flaw can be mitigated by setting the sysctl parameter (/proc/sys/net/ipv4/tcp_min_rtt_wlen) with 300 which means the packet time will not exceed more then 5 minutes and which should not cause an integer overflow.
CVSS / CWE
CVSS 3.0 · 7.3CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:H
CWE-190 · Integer Overflow or Wraparound