MEDIUM
In the Linux kernel before 5.1.7, a device can be tracked by an attacker using the IP ID values the kernel produces for connection-less protocols (e.g., UDP and ICMP). When such traffic is sent to multiple destination IP addresses, it is possible to obtain hash collisions (of indices to the counter array) and thereby obtain the hashing key (via enumeration). An attack may be conducted by hosting a crafted web page that uses WebRTC or gQUIC to force UDP traffic to attacker-controlled IP addresses.
http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00014.html
http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00025.html
http://www.securityfocus.com/bid/109092
https://arxiv.org/pdf/1906.10478.pdf
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.0.8
https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.1.7
https://github.com/torvalds/linux/commit/355b98553789b646ed97ad801a619ff898471b92
https://github.com/torvalds/linux/commit/55f0fc7a02de8f12757f4937143d8d5091b2e40b
https://github.com/torvalds/linux/commit/df453700e8d81b1bdafdf684365ee2b9431fb702
https://lists.debian.org/debian-lts-announce/2019/08/msg00016.html
https://lists.debian.org/debian-lts-announce/2019/08/msg00017.html
https://seclists.org/bugtraq/2019/Aug/13
https://seclists.org/bugtraq/2019/Aug/18
https://security.netapp.com/advisory/ntap-20190806-0001/
https://usn.ubuntu.com/4114-1/
https://usn.ubuntu.com/4115-1/
https://usn.ubuntu.com/4116-1/
https://usn.ubuntu.com/4117-1/
https://usn.ubuntu.com/4118-1/
Source: MITRE
Published: 2019-07-05
Updated: 2019-07-19
Type: CWE-200
Base Score: 4.3
Vector: AV:N/AC:M/Au:N/C:P/I:N/A:N
Impact Score: 2.9
Exploitability Score: 8.6
Severity: MEDIUM
Base Score: 6.5
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
Impact Score: 3.6
Exploitability Score: 2.8
Severity: MEDIUM