base_sock_create in drivers/isdn/mISDN/socket.c in the AF_ISDN network module in the Linux kernel through 5.3.2 does not enforce CAP_NET_RAW, which means that unprivileged users can create a raw socket, aka CID-b91ee4aa2a21.
lists.opensuse.org/opensuse-security-announce/2019-11/msg00035.html
lists.opensuse.org/opensuse-security-announce/2019-11/msg00039.html
packetstormsecurity.com/files/155212/Slackware-Security-Advisory-Slackware-14.2-kernel-Updates.html
access.redhat.com/errata/RHSA-2020:0790
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0edc3f703f7bcaf550774b5d43ab727bcd0fe06b
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b91ee4aa2a2199ba4d4650706c272985a5a32d80
lists.debian.org/debian-lts-announce/2020/01/msg00013.html
lists.debian.org/debian-lts-announce/2020/03/msg00001.html
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/U6JNEWGIK7QA24OIUUL67QZNJN52NB7T/
seclists.org/bugtraq/2019/Nov/11
usn.ubuntu.com/4184-1/
usn.ubuntu.com/4185-1/
usn.ubuntu.com/4185-2/
usn.ubuntu.com/4186-1/
usn.ubuntu.com/4186-2/