Moderate: ruby security update

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.

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.

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

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

http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-1145
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-3443
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-3655
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-3656
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-3657
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-3790
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2008-3905
http://www.redhat.com/security/updates/classification/#moderate