Debian 9 Stretch DLA-2713-2 Critical: Kernel Privilege Escalation

CVE-2021-3609

Norbert Slusarek reported a race condition vulnerability in the CAN
BCM networking protocol, allowing a local attacker to escalate
privileges.

CVE-2021-21781

"Lilith >_>" of Cisco Talos discovered that the Arm initialisation
code does not fully initialise the "sigpage" that is mapped into
user-space processes to support signal handling. This could
result in leaking sensitive information, particularly when the
system is rebooted.

CVE-2021-33909

The Qualys Research Labs discovered a size_t-to-int conversion
vulnerability in the Linux kernel's filesystem layer. An
unprivileged local attacker able to create, mount, and then delete a
deep directory structure whose total path length exceeds 1GB, can
take advantage of this flaw for privilege escalation.

Details can be found in the Qualys advisory at
https://www.qualys.com/2021/07/20/cve-2021-33909/sequoia-local-privilege-escalation-linux.txt

CVE-2021-34693