A flaw was found in the HDLC_PPP module of the Linux kernel in versions before 5.9-rc7. Memory corruption and a read overflow is caused by improper input validation in the ppp_cp_parse_cr function which can cause the system to crash or cause a denial of service. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
https://www.starwindsoftware.com/security/sw-20210325-0002/
https://www.debian.org/security/2020/dsa-4774
https://security.netapp.com/advisory/ntap-20201103-0002/
https://lists.debian.org/debian-lts-announce/2020/10/msg00034.html
https://lists.debian.org/debian-lts-announce/2020/10/msg00032.html
https://lists.debian.org/debian-lts-announce/2020/10/msg00028.html
https://bugzilla.redhat.com/show_bug.cgi?id=1879981
http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00042.html
http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00021.html