RHSA-2011:1581 - Security Advisory

Topic

Updated ruby packages that fix two security issues, various bugs, and add
one enhancement are now available for Red Hat Enterprise Linux 6.

The Red Hat Security Response Team has rated this update as having low
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 found that Ruby did not reinitialize the PRNG (pseudorandom number
generator) after forking a child process. This could eventually lead to the
PRNG returning the same result twice. An attacker keeping track of the
values returned by one child process could use this flaw to predict the
values the PRNG would return in other child processes (as long as the
parent process persisted). (CVE-2011-3009)

A flaw was found in the Ruby SecureRandom module. When using the
SecureRandom.random_bytes class, the PRNG state was not modified after
forking a child process. This could eventually lead to
SecureRandom.random_bytes returning the same string more than once. An
attacker keeping track of the strings returned by one child process could
use this flaw to predict the strings SecureRandom.random_bytes would return
in other child processes (as long as the parent process persisted).
(CVE-2011-2705)

This update also fixes the following bugs:

• The ruby package has been upgraded to upstream point release 1.8.7-p352,

which provides a number of bug fixes over the previous version. (BZ#706332)

• The MD5 message-digest algorithm is not a FIPS-approved algorithm.

Consequently, when a Ruby script attempted to calculate an MD5 checksum in
FIPS mode, the interpreter terminated unexpectedly. This bug has been fixed
and an exception is now raised in the described scenario. (BZ#717709)

• Due to inappropriately handled line continuations in the mkconfig.rb

source file, an attempt to build the ruby package resulted in unexpected
termination. An upstream patch has been applied to address this issue and
the ruby package can now be built properly. (BZ#730287)

• When the 32-bit ruby-libs library was installed on a 64-bit machine, the

mkmf library failed to load various modules necessary for building
Ruby-related packages. This bug has been fixed and mkmf now works properly
in the described scenario. (BZ#674787)

• Previously, the load paths for scripts and binary modules were duplicated

on the i386 architecture. Consequently, an ActiveSupport test failed. With
this update, the load paths are no longer stored in duplicates on the i386
architecture. (BZ#722887)

This update also adds the following enhancement:

• With this update, SystemTap probes have been added to the ruby package.

(BZ#673162)

All users of ruby are advised to upgrade to these updated packages, which
resolve these issues and add this enhancement.

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/kb/docs/DOC-11259

Affected Products

• Red Hat Enterprise Linux Server 6 x86_64
• Red Hat Enterprise Linux Server 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 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 Power, big endian 6 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 Life Cycle Support (for IBM z Systems) 6 s390x

Fixes

• BZ - 673162 - RFE: add systemtap static probes to Ruby
• BZ - 674787 - multilib breaks mkmf.rb
• BZ - 706332 - Update Ruby to the latest point release
• BZ - 717709 - MD5 makes ruby interpreter crash in FIPS mode
• BZ - 722415 - CVE-2011-2686 CVE-2011-2705 CVE-2011-3009 ruby: Properly initialize the random number generator when forking new process
• BZ - 722887 - Load paths duplicated for i386 =>ActiveSupport build fails on i386
• BZ - 730287 - It's not possible to build ruby package

CVEs

• CVE-2011-2705
• CVE-2011-3009

References

• https://access.redhat.com/security/updates/classification/#low