RHSA-2014:1801 - Security Advisory

Topic

Updated shim packages that fix three security issues are now available for
Red Hat Enterprise Linux 7.

Red Hat Product Security has rated this update as having Moderate security
impact. Common Vulnerability Scoring System (CVSS) base scores, which give
detailed severity ratings, are available for each vulnerability from the
CVE links in the References section.

Description

Shim is the initial UEFI bootloader that handles chaining to a trusted full
bootloader under secure boot environments.

A heap-based buffer overflow flaw was found the way shim parsed certain
IPv6 addresses. If IPv6 network booting was enabled, a malicious server
could supply a crafted IPv6 address that would cause shim to crash or,
potentially, execute arbitrary code. (CVE-2014-3676)

An out-of-bounds memory write flaw was found in the way shim processed
certain Machine Owner Keys (MOKs). A local attacker could potentially use
this flaw to execute arbitrary code on the system. (CVE-2014-3677)

An out-of-bounds memory read flaw was found in the way shim parsed certain
IPv6 packets. A specially crafted DHCPv6 packet could possibly cause shim
to crash, preventing the system from booting if IPv6 booting was enabled.
(CVE-2014-3675)

Red Hat would like to thank the SUSE Security Team for reporting these
issues.

All shim users are advised to upgrade to these updated packages, which
contain backported patches to correct these issues. The system must be
rebooted for this update to take effect.

Solution

Before applying this update, make sure all previously released errata
relevant to your system have been applied.

This update is available via the Red Hat Network. Details on how to
use the Red Hat Network to apply this update are available at
https://access.redhat.com/articles/11258

Affected Products

• Red Hat Enterprise Linux Server 7 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.7 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.6 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.5 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.4 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.3 x86_64
• Red Hat Enterprise Linux Server from RHUI 7 x86_64
• Red Hat Enterprise Linux Server - AUS 7.7 x86_64
• Red Hat Enterprise Linux Server - AUS 7.6 x86_64
• Red Hat Enterprise Linux Server - AUS 7.4 x86_64
• Red Hat Enterprise Linux Server - AUS 7.3 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 7 x86_64
• Red Hat Enterprise Linux Workstation 7 x86_64
• Red Hat Enterprise Linux Desktop 7 x86_64
• Red Hat Enterprise Linux for Scientific Computing 7 x86_64
• Red Hat Enterprise Linux Server - TUS 7.7 x86_64
• Red Hat Enterprise Linux Server - TUS 7.6 x86_64
• Red Hat Enterprise Linux Server - TUS 7.3 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.7 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.6 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.5 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.4 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.3 x86_64
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.7 x86_64
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.6 x86_64
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.4 x86_64
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.3 x86_64

Fixes

• BZ - RHSA-2014:1801 - CVE-2014-3675 shim: out-of-bounds memory read flaw in DHCPv6 packet processing
• BZ - RHSA-2014:1801 - CVE-2014-3676 shim: heap-based buffer overflow flaw in IPv6 address parsing
• BZ - RHSA-2014:1801 - CVE-2014-3677 shim: memory corruption flaw when processing Machine Owner Keys (MOKs)

CVEs

• CVE-2014-3675
• CVE-2014-3676
• CVE-2014-3677

References

• http://www.redhat.com/security/updates/classification/#normal