HIGH
In the Linux kernel, a certain net/ipv4/tcp_output.c change, which was properly incorporated into 4.16.12, was incorrectly backported to the earlier longterm kernels, introducing a new vulnerability that was potentially more severe than the issue that was intended to be fixed by backporting. Specifically, by adding to a write queue between disconnection and re-connection, a local attacker can trigger multiple use-after-free conditions. This can result in a kernel crash, or potentially in privilege escalation. NOTE: this affects (for example) Linux distributions that use 4.9.x longterm kernels before 4.9.190 or 4.14.x longterm kernels before 4.14.139.
http://lists.opensuse.org/opensuse-security-announce/2019-09/msg00064.html
http://lists.opensuse.org/opensuse-security-announce/2019-09/msg00066.html
https://lore.kernel.org/stable/[email protected]/
https://pulsesecurity.co.nz/advisories/linux-kernel-4.9-tcpsocketsuaf
Source: MITRE
Published: 2019-08-20
Updated: 2019-09-24
Type: CWE-416
Base Score: 7.2
Vector: AV:L/AC:L/Au:N/C:C/I:C/A:C
Impact Score: 10
Exploitability Score: 3.9
Severity: HIGH
Base Score: 7.8
Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Impact Score: 5.9
Exploitability Score: 1.8
Severity: HIGH