Re: CVE request: kernel: /sys/kernel/debug/acpi/custom_method can bypass module restrictions

[Eugene Teo <eugene () redhat com>]

On 02/25/2011 08:32 AM, Kees Cook wrote:
> Hi,
>
> While CVE-2010-4347 covers the unprivileged to fully privileged escalation
> issue, this interface still allows an unprivileged root user to gain
> back all their capabilities.
>
> Having a system with acpi and debugfs built into the kernel allows
> a uid=0 user (without capabilities, e.g. in containers) to write to
> arbitrary kernel memory, likely resulting in escalated capability
> privileges[1], or unlocking an otherwise modules-disabled kernel by
> changing /proc/sys/kernel/modules_disabled back to 0.

Use CVE-2011-1021.

Eugene
--
Eugene Teo / Red Hat Security Response Team