(RHSA-2008:0897) Moderate: ruby security update

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.