RHSA-2013:0612 - Security Advisory

Topic

Updated ruby packages that fix two security issues are now available for
Red Hat Enterprise Linux 6.

The Red Hat Security Response Team 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

Ruby is an extensible, interpreted, object-oriented, scripting language. It
has features to process text files and to do system management tasks.

It was discovered that Ruby's REXML library did not properly restrict XML
entity expansion. An attacker could use this flaw to cause a denial of
service by tricking a Ruby application using REXML to read text nodes from
specially-crafted XML content, which will result in REXML consuming large
amounts of system memory. (CVE-2013-1821)

It was found that the RHSA-2011:0910 update did not correctly fix the
CVE-2011-1005 issue, a flaw in the method for translating an exception
message into a string in the Exception class. A remote attacker could use
this flaw to bypass safe level 4 restrictions, allowing untrusted (tainted)
code to modify arbitrary, trusted (untainted) strings, which safe level 4
restrictions would otherwise prevent. (CVE-2012-4481)

The CVE-2012-4481 issue was discovered by Vit Ondruch of Red Hat.

All users of Ruby are advised to upgrade to these updated packages, which
contain backported patches to resolve these issues.

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/knowledge/articles/11258

Affected Products

• Red Hat Enterprise Linux Server 6 x86_64
• Red Hat Enterprise Linux Server 6 i386
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.4 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.4 i386
• Red Hat Enterprise Linux Server - AUS 6.4 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 i386
• Red Hat Enterprise Linux Workstation 6 x86_64
• Red Hat Enterprise Linux Workstation 6 i386
• Red Hat Enterprise Linux Desktop 6 x86_64
• Red Hat Enterprise Linux Desktop 6 i386
• Red Hat Enterprise Linux for IBM z Systems 6 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 6.4 s390x
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 6.4 ppc64
• Red Hat Enterprise Linux for Scientific Computing 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 i386
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.4 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.4 i386
• Red Hat Gluster Storage Server for On-premise 2.1 x86_64
• Red Hat Storage for Public Cloud (via RHUI) 2.1 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 x86_64
• Red Hat Enterprise Linux for Power, big endian 6 ppc64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 6 s390x

Fixes

• BZ - 863484 - CVE-2012-4481 ruby: Incomplete fix for CVE-2011-1005 for NameError#to_s method when used on objects
• BZ - 914716 - CVE-2013-1821 ruby: entity expansion DoS vulnerability in REXML

CVEs

• CVE-2012-4481
• CVE-2013-1821

References

• https://access.redhat.com/security/updates/classification/#moderate
• https://rhn.redhat.com/errata/RHSA-2011-0910.html