RHSA-2008:0897 - Security Advisory

Topic

Updated ruby packages that fix several security issues are now available
for Red Hat Enterprise Linux 4 and 5.

This update has been rated as having moderate security impact by the Red
Hat Security Response Team.

Description

Ruby is an interpreted scripting language for quick and easy
object-oriented programming.

The Ruby DNS resolver library, resolv.rb, used predictable transaction IDs
and a fixed source port when sending DNS requests. A remote attacker could
use this flaw to spoof a malicious reply to a DNS query. (CVE-2008-3905)

Ruby's XML document parsing module (REXML) was prone to a denial of service
attack via XML documents with large XML entity definitions recursion. A
specially-crafted XML file could cause a Ruby application using the REXML
module to use an excessive amount of CPU and memory. (CVE-2008-3790)

An insufficient "taintness" check flaw was discovered in Ruby's DL module,
which provides direct access to the C language functions. An attacker could
use this flaw to bypass intended safe-level restrictions by calling
external C functions with the arguments from an untrusted tainted inputs.
(CVE-2008-3657)

A denial of service flaw was discovered in WEBrick, Ruby's HTTP server
toolkit. A remote attacker could send a specially-crafted HTTP request to a
WEBrick server that would cause the server to use an excessive amount of
CPU time. (CVE-2008-3656)

A number of flaws were found in the safe-level restrictions in Ruby. It
was possible for an attacker to create a carefully crafted malicious script
that can allow the bypass of certain safe-level restrictions. (CVE-2008-3655)

A denial of service flaw was found in Ruby's regular expression engine. If
a Ruby script tried to process a large amount of data via a regular
expression, it could cause Ruby to enter an infinite-loop and crash.
(CVE-2008-3443)

Users of ruby should upgrade to these updated packages, which contain
backported patches to resolve these issues.

Solution

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

This update is available via Red Hat Network. Details on how to use
the Red Hat Network to apply this update are available at
http://kbase.redhat.com/faq/FAQ_58_10188

Affected Products

• Red Hat Enterprise Linux Server 5 x86_64
• Red Hat Enterprise Linux Server 5 ia64
• Red Hat Enterprise Linux Server 5 i386
• Red Hat Enterprise Linux Server 4 x86_64
• Red Hat Enterprise Linux Server 4 ia64
• Red Hat Enterprise Linux Server 4 i386
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.2 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.2 ia64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.2 i386
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 4.7 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 4.7 ia64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 4.7 i386
• Red Hat Enterprise Linux Workstation 5 x86_64
• Red Hat Enterprise Linux Workstation 5 i386
• Red Hat Enterprise Linux Workstation 4 x86_64
• Red Hat Enterprise Linux Workstation 4 ia64
• Red Hat Enterprise Linux Workstation 4 i386
• Red Hat Enterprise Linux Desktop 5 x86_64
• Red Hat Enterprise Linux Desktop 5 i386
• Red Hat Enterprise Linux Desktop 4 x86_64
• Red Hat Enterprise Linux Desktop 4 i386
• Red Hat Enterprise Linux for IBM z Systems 5 s390x
• Red Hat Enterprise Linux for IBM z Systems 4 s390x
• Red Hat Enterprise Linux for IBM z Systems 4 s390
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 5.2 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 4.7 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 4.7 s390
• Red Hat Enterprise Linux for Power, big endian 5 ppc
• Red Hat Enterprise Linux for Power, big endian 4 ppc
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 5.2 ppc
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 4.7 ppc
• Red Hat Enterprise Linux Server from RHUI 5 x86_64
• Red Hat Enterprise Linux Server from RHUI 5 i386

Fixes

• BZ - 458948 - CVE-2008-3655 ruby: multiple insufficient safe mode restrictions
• BZ - 458953 - CVE-2008-3656 ruby: WEBrick DoS vulnerability (CPU consumption)
• BZ - 458966 - CVE-2008-3657 ruby: missing "taintness" checks in dl module
• BZ - 459266 - CVE-2008-3443 ruby: Memory allocation failure in Ruby regex engine (remotely exploitable DoS)
• BZ - 460134 - CVE-2008-3790 ruby: DoS vulnerability in the REXML module
• BZ - 461495 - CVE-2008-3905 ruby: use of predictable source port and transaction id in DNS requests done by resolv.rb module

CVEs

• CVE-2008-3655
• CVE-2008-3657
• CVE-2008-3656
• CVE-2008-3790
• CVE-2008-3905
• CVE-2008-3443
• CVE-2008-1145

References

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