This wording appears to have caused a lot of misunderstanding. afaict,
the binary executable ‘cryptsetup’ has nothing to do with this bug.
Rather, it is completely in the initrd’s script for decrypting a
partition containing the rootfs.
On Debian based systems, the initrd script is in the cryptsetup package,
but if one looks at the upstream repository for cryptsetup:
Nginx web server packaging on Debian-based distributions such as Debian or
Ubuntu was found to create log directories with insecure permissions which
can be exploited by malicious local attackers to escalate their privileges
from nginx/web user (www-data) to root.
The vulnerability…
Description
———–
A vulnerability in Cryptsetup, concretely in the scripts that unlock the
system partition when the partition is ciphered using LUKS (Linux
Unified Key Setup).
This vulnerability allows to obtain a root initramfs shell on affected
systems. The vulnerability is very reliable because it doesn’t depend on
specific systems or…
OS-S Security Advisory 2016-21
Local DoS: Linux Kernel Nullpointer Dereference via keyctl
Date:
October 31th, 2016
Authors:
Sergej Schumilo, Ralf Spenneberg, Hendrik Schwartke
CVE:
Not yet assigned
CVSS:
4.9 (AV:L/AC:L/Au:N/C:N/I:N/A:C)
Severity:
Potentially critical. If the kernel is compiled with the option
“Panic-On-Oops”, this vulnerability may lead to a kernel panic.
Ease of Exploitation:
Trivial
Vulnerability Type:
Local unprivileged…
Throughout November, I plan to release details on vulnerabilities I
found in web-browsers which I’ve not released before. This is the
eleventh entry in that series. Unfortunately I won’t be able to publish
everything within one month at the current rate, so I may continue to
publish these through December and January.