Arch Linux alert ASA-202105-17 (runc)

From:
             
 
Jonas Witschel via arch-security <arch-security@lists.archlinux.org>
To:
             
 
arch-security@lists.archlinux.org
Subject:
             
 
[ASA-202105-17] runc: sandbox escape
Date:
             
 
Wed, 26 May 2021 12:32:22 +0200
Message-ID:
             
 
<20210526103222.526xzoomy747k7cy@archlinux.org>
Cc:
             
 
Jonas Witschel <diabonas@archlinux.org>
Arch Linux Security Advisory ASA-202105-17
==========================================

Severity: High
Date    : 2021-05-25
CVE-ID  : CVE-2021-30465
Package : runc
Type    : sandbox escape
Remote  : No
Link    : https://security.archlinux.org/AVG-1972

Summary
=======

The package runc before version 1.0.0rc95-1 is vulnerable to sandbox
escape.

Resolution
==========

Upgrade to 1.0.0rc95-1.

# pacman -Syu "runc>=1.0.0rc95-1"

The problem has been fixed upstream in version 1.0.0rc95.

Workaround
==========

Container hardening mechanisms such as LSMs (AppArmor/SELinux) and user
namespaces can restrict the amount of damage an attacker could do but
they do not block this attack outright.

Description
===========

runc 1.0.0-rc94 and earlier are vulnerable to a symlink exchange attack
where an attacker with the ability to start containers using a custom
volume configuration can request a seemingly-innocuous container
configuration that results in the host filesystem being bind-mounted
into the container (allowing for a container escape).

Impact
======

An attacker can escape from a container and access arbitrary files on
the host system using a crafted container configuration.

References
==========

https://github.com/opencontainers/runc/security/advisorie...
https://github.com/opencontainers/runc/commit/0ca91f44f16...
https://security.archlinux.org/CVE-2021-30465